Chocolatey brownie squares, topped with a creamy thick layer of light, smooth peanut butter Swiss meringue buttercream frosting – these peanut butter frosted brownies are sure to please any crowd!
These peanut butter frosted brownies are decadent, chocolatey, and oh-so-good. Plus, you can make a big batch so everyone can get their fix. Best of all, they’re easy to make and can be adapted to include your favorite add-ins: Reese’s Peanut Butter Cups, Reese’s Pieces, a simple peanut butter drizzle, peanuts, and more. Whether you’re hosting a party or just need a sweet treat for yourself, these brownies are sure to hit the spot. I’m so excited for you to try them today!
This peanut butter brownies recipe may very well be my most favorite brownie recipe I’ve ever made. It’s easy to make with simple ingredients, chalk full of delicious chocolate and peanut butter flavor and is perfectly sweet even with that thick layer of frosting. Made with a swiss meringue buttercream instead of a super sweet American buttercream this brownies recipe will satisfy your sweet tooth but not overload your taste buds.
HOW TO MAKE PEANUT BUTTER FROSTED BROWNIES:
I shared the base brownie recipe for these brownies a few weeks ago. They are our favorite go-to brownies for good reason! They taste amazing as a Plain Jane style but are perfect for variations. These peanut butter frosted brownies are one of those variations and my absolute favorite so far.
HOW TO MAKE SHEET BROWNIES:
To make the brownies, it’s easy and uses very simple ingredients. You can find the full printable recipe at the bottom of this post. For the brownie base you’ll need:
- Butter
- Sugar
- Brown sugar
- Eggs
- Vanilla
- All-purpose flour
- Cocoa powder
- Salt
The brownie batter can be made in a large bowl using a hand mixer or in a stand mixer. Be aware though that this batter is very thick when it’s done. It can easily burn out a hand mixer if not powerful enough.
For the batter start with the creaming method. This is were you cream the butter and sugars together until they are very well mixed, lighter in color and fluffy. Once creamed, the eggs and vanilla are added. Lastly, the flour cocoa and salt are mixed together than added.
It is important to get the dry ingredients fully mixed in without OVERMIXING the batter. A few small clumps in the batter are ok.
Once the batter is mixed pour into a cookie sheet. Yes, that’s right. A cookie sheet! This brownie recipe makes a LARGE batch and you’ll be glad you have so many.
Bake for 30 minutes.
PRO TIME SAVER TIP: While the brownies are baking, make the light and airy peanut butter swiss meringue frosting.
SWISS MERINGUE BUTTERCREAM VS ITALIAN BUTTERCREAM VS FRENCH MERINGUE BUTTERCREAM
Swiss meringue buttercream is the smoothest, silkiest of the three types of meringue buttercreams. All three kinds are made with similar ingredients and are not overly sweet like American buttercream. Here are some key differences to each:
Swiss Meringue Buttercream (SMBC):
- Smoothest, silky texture
- Made by heating egg whites and sugar together until sugar has dissolved. Mixture is whipped to stiff peaks then unsalted butter is added
- Can be made to be very white with the addition of a drop or two of purple food coloring
- The least stable of the three kinds
Italian Meringue Buttercream (IMBC):
- Made by adding hot sugar syrup to whipped egg whites then adding butter
- The most stable of the three kinds
- Can be made very white like SMBC
French Meringue Buttercream (FMBC):
- Made by adding hot sugar syrup to foamy egg YOLKS then adding butter
- Has a much higher fat content than the other two kinds of buttercream
- Ivory in color due to the use of egg yolks instead of egg whites
- Is not as stable due to the higher fat content
- Most similar to a pastry cream
I love using swiss meringue buttercream because of its light, smooth texture and ice cream-like flavor and sweetness.
HOW TO MAKE PEANUT BUTTER SWISS MERINGUE BUTTERCREAM:
This frosting is SOOO dang good! It’s light, smooth, sweet but not too sweet. Unlike traditional American buttercream, swiss meringue buttercream is smoother, lighter and not as sweet. My husband thinks it should be a dessert on its own. HAHA.
Ingredients needed:
- Egg whites
- Sugar
- Salt
- Vanilla
- UNSALTED butter
- Creamy peanut butter
For the WOW factor topping:
- Reese’s Peanut Butter Cups
- Chocolate ganache (chocolate chips and whipping cream)
Start by heating the egg whites, sugar and fine salt using a double broiler method. This is done by using by taking a bowl slightly bigger bigger then your pot and placing it over the pot of simmering water.
PRO TIP: Make sure the bowl is not touching the simmering water.
Slowly heat the egg sugar mixture until all the sugar crystals have dissolved. This usually only takes 5 minutes or so.
Whip the mixture using a stand mixer (recommended) or a hand mixer until it is light a fluffy. It will triple or quadruple in size, become very white, shine and fluffy.
After the meringue mixture has been whipped to stiff peaks (can take up to 15 minutes) AND has cooled to room temperature (70-75F.) switch the whisk attachment to the paddle attachment then begin adding a tablespoon of room temperature unsalted butter at a time.
The mixture will be soft, almost runny until all the butter has been added and incorporated. The mixture will need to be mixed for 5 to 10 minutes after the last pieces of butter have been added. During this time you can add liquid flavorings (vanilla) and color if desired. You know it’s done when it no longer tastes like butter but instead, tastes like ice cream.
The buttercream will be thick, smooth and creamy. When it reaches this point fold in the peanut butter. It’s ready!
DID YOU KNOW YOU CAN USE SWISS MERINGUE BUTTERCREAM UNDER FONDANT?
It’s true! You can use SMBC under fondant. I’ve done it several times. It’s my preferred frosting even when making a layered cake or fondant-covered wedding cake.
FAQs
WHY IS MY PEANUT BUTTER SWISS MERINGUE BUTTERCREAM GRAINY?
If the buttercream comes out feeling sugary or grainy, this is because the sugar wasn’t completely dissolved in the first step (heating). To avoid this, make sure you heat the egg white/sugar mixture long enough to dissolve all sugar crystals (thermometer should read around 160F. when it’s ready). You can also check by dipping a finger into the mixture then rubbing it to your thumb. If you feel grains, it’s not ready. If it’s smooth, you’re good to go.
Make sure not to go to much higher than 160F. as the egg whites will begin to cook.
WHY DOES MY BUTTERCREAM LOOK LUMPY LIKE IT HAS CURDLED?
This usually just means it’s too cold. To make it smooth, heat a small amount (1/4 cup) of the mixture in the microwave for 15-20 seconds then mix it back in. This will heat up the rest of the buttercream and make it smooth.
HELP! MY SMBC IS RUNNY! CAN IT BE FIXED?
This can happen if the butter is added when the meringue is too warm OR the butter hasn’t fully been incorporated. Can it be salvaged… usually yes! Feel the bowl. Is it still warm? If it is, put the bowl of buttercream in the fridge for 20-30 minutes then resume mixing. If the bowl is not warm, then keep mixing. It’s likely that the butter hasn’t fully incorporated into the meringue. This can take several (5-10) minutes of mixing after the last pieces of butter have been added.
HOW MANY BROWNIES DOES THIS RECIPE MAKE?
This peanut butter frosted brownies recipe will make a whooping 48 delectable and decent-sized brownies. That is if you cut them into about 2×2 squares. If you want to make jumbo 3×3 brownies, like the $3 brownies you can buy from the bakery… then you’ll get 24. We absolutely love this recipe for potlucks and large gatherings. We enjoyed these brownies Plain-Jane-Style at our family reunion.
DO YOU REALLY NEED THAT MUCH BUTTERCREAM?
The Peanut Butter Swiss Meringue Buttercream is so light, smooth and NOT overly sweet like a traditional American buttercream, it allows you to load it on without having a sugar overload. That said, if you’d prefer a lighter amount of buttercream, feel free to half the buttercream recipe. Instead of having about a 1/2 inch of buttercream you will end up with about a 1/4 inch.
In my opinion, the buttercream atop these Peanut Butter Frosted Brownies isn’t to thick because its light, smooth and gently sweetened especially compared to ultra sweet American buttercream.
HERE’S THE FULL PRINTABLE RECIPE. ENJOY!
Peanut Butter Frosted Brownies
Chocolatey brownie squares, topped with light, smooth peanut butter swiss meringue buttercream - these brownies are sure to please any crowd!
Ingredients
Brownie Layer:
- 2 cups softened butter, 1 lb
- 3 cups white sugar, 600 g
- 1 cup brown sugar, 210 g
- 8 eggs, 18 oz
- 1 Tbs vanilla
- 3 cups all-purpose flour, 360 g
- 3/4 cups cocoa powder, about 65 g
- 3/4 tsp salt
Peanut Butter Swiss Meringue Buttercream:
- 6 large egg whites, about 240 g
- 2 cups granulated sugar, 400 g
- 1/4 tsp salt
- 1 1/2 cups UNSALTED butter, room temperature, 340 g
- 2 tsp. vanilla
- 2/3 cup creamy peanut butter, 260 g
Chocolate Ganache & PB Cups:
- 6oz chocolate chips (semi sweet or milk chocolate, whichever you prefer)
- 1/4 cup cream, 2oz
- 8-16 regular Reese's peanut butter cups (4-8 regular size candy bars)
Instructions
BROWNIE LAYER:
- Cream the butter, white sugar, and brown sugar together with a stand mixer - about 2 or 3 minutes. Slowly add the eggs in one at a time. Once fully incorporated mix in the vanilla.
- In a separate bowl, mix the flour, cocoa powder and salt.
- Gradually add the dry ingredients to the batter mixture until combined. The batter should be thick and similar to a soft cookie dough. Do not over mix the batter. Stop mixing immediately once the dry ingredients are incorporated.
- Spread the brownie batter evenly on the cookie sheet pan. Bake for 30 minutes or until a toothpick poked into the center of the brownies comes out clean.
- Once the brownies are done let them cool completely before frosting.
PEANUT BUTTER SWISS MERINGUE BUTTERCREAM:
- While the brownies are baking, using a double boiler to heat egg whites, sugar and salt over simmering water. Make sure the bowl does not touch the simmering water. Stir mixture. Heat until mixture reaches 160F and sugar has dissolved (about 4-5 minutes). Test if sugar has dissolved by rubbing the mixture between two fingers. It should feel smooth with no grains.
- When mixture is ready. Wipe bottom of bowl to remove any moisture then carefully pour mixture into a stand mixer bowl with a whisk attachment. Whip egg white mixture until it turns white, glossy and triples or quadruples in volume (10-15 minutes). The mixture should be very thick and fluffy. During this time the mixture will begin to cool. This is critical. Before adding the unsalted butter, the meringue mixture must be cool enough (70-75F) or the butter will melt.
- Once the mixture has cooled to 70-75F, switch to the paddle attachment. Begin adding one tablespoon of room temperature unsalted butter. Make sure each piece has been incorporated into the meringue before adding that next piece. After all the butter has been added, add vanilla. Mix buttercream for an additional 7-10 minutes. It is ready when the buttercream no longer tastes like butter but rather like ice cream.
- Lastly, fold in peanut butter.
CHOCOLATE GANACHE & PEANUT BUTTER CUPS:
- In a microwave safe bowl, add chocolate chips and cream. Heat in the microwave for 45-60 seconds until the cream is very warm. Let stand 2-3 minutes. Begin stirring in a tight circle in the middle. As the chocolate and cream begin to incorporate widen the circle until all cream has been incorporated and the ganache is a dark rich color. Pour in a glazing bottle, ziploc bag or piping bag when ready to drizzle on brownies.
- Chop peanut butter cups in to small chunks.
ASSEMBLING PEANUT BUTTER FROSTED BROWNIES:
- Evenly spread peanut butter frosting over sheet of brownies.
- Sprinkle chopped peanut butter cups over frosting. Lightly press peanut butter cups into the buttercream.
- drizzle chocolate ganache over peanut butter frosted brownies. Let cool and set for 20-30 minutes before cutting.
- Cut the sheet of Peanut Butter Frosted Brownies into squares--24 very large 3x3 inch brownies or 48 2x2 inch "regular" size brownies.
Notes
FAQs
WHY IS MY PEANUT BUTTER SWISS MERINGUE BUTTERCREAM GRAINY?
If the buttercream comes out feeling sugary or grainy, this is because the sugar wasn't completely dissolved in the first step (heating). To avoid this, make sure you heat the egg white/sugar mixture long enough to dissolve all sugar crystals (thermometer should read around 160F. when it's ready). You can also check by dipping a finger into the mixture then rubbing it to your thumb. If you feel grains, it's not ready. If it's smooth, you're good to go.
Make sure not to go to much higher than 160F. as the egg whites will begin to cook.
WHY DOES MY BUTTERCREAM LOOK LUMPY LIKE IT HAS CURDLED?
This usually just means it's too cold. To make it smooth, heat a small amount (1/4 cup) of the mixture in the microwave for 15-20 seconds then mix it back in. This will heat up the rest of the buttercream and make it smooth.
HELP! MY SMBC IS RUNNY! CAN IT BE FIXED?
This can happen if the butter is added when the meringue is too warm OR the butter hasn't fully been incorporated. Can it be salvaged... usually yes! Feel the bowl. Is it still warm? If it is, put the bowl of buttercream in the fridge for 20-30 minutes then resume mixing. If the bowl is not warm, then keep mixing. It's likely that the butter hasn't fully incorporated into the meringue. This can take several (5-10) minutes of mixing after the last pieces of butter have been added.
HOW MANY BROWNIES DOES THIS RECIPE MAKE?
This peanut butter frosted brownies recipe will make a whooping 48 delectable and decent-sized brownies. That is if you cut them into about 2x2 squares. If you want to make jumbo 3x3 brownies, like the $3 brownies you can buy from the bakery... then you'll get 24. We absolutely love this recipe for potlucks and large gatherings. We enjoyed these brownies Plain-Jane-Style at our family reunion.
DO YOU REALLY NEED THAT MUCH BUTTERCREAM?
The Peanut Butter Swiss Meringue Buttercream is so light, smooth and NOT overly sweet like a traditional American buttercream, it allows you to load it on without having a sugar overload. That said, if you'd prefer a lighter amount of buttercream, feel free to half the buttercream recipe. Instead of having about a 1/2 inch of buttercream you will end up with about a 1/4 inch.
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Nutrition Information:
Yield: 48 Serving Size: 1Amount Per Serving: Calories: 456Total Fat: 28gSaturated Fat: 13gTrans Fat: 0gUnsaturated Fat: 12gCholesterol: 354mgSodium: 287mgCarbohydrates: 39gFiber: 1gSugar: 30gProtein: 14g
Buttercream Recipe adapted from Sally’s Baking Addition.
In my opinion, when you want to take some snack to yourself, brownie is the easy and fast to bake.