Preheat your oven to 350F. Prepare a 9x13 inch pan with cooking spray or line with parchment paper.

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 into prepared 9x13 pan. Bake for 25-30 minutes or until a toothpick poked into the center of the brownies comes out clean.

Once the brownies are done let them cool. Cut brownies into same shape as the serving glass or in small cubes. Depending on the size of serving glass you may get more or less yield.

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 on high until it turns white, glossy and significantly increases in volume (5-10 minutes). The mixture should be very thick and fluffy. During this time the mixture will begin to cool.

Once fully whipped slowly add vanilla. Whip for an additional 1-2 minutes.

Now for the fun part! Once the brownies have cooled you can assemble the dessert cups. I used small 9-11oz cups. For convenience, I made several in clear 9oz tumbler cups I picked up at Costco. Depending on the size of cup or serving dish used, quantities may differ.

Add the first layer of crushed graham cracker. Use 2-3 tablespoons depending on how fine your crackers are crushed.

Next, add a layer of marshmallow meringue. This should be about as thick as your graham cracker layer.

Then, sprinkle another layer of cracker, the same as before, about 2-3 tablespoons.

Add the brownie layer next. Either use one circle cut to the size of the cup or cubes making a single layer.

Next, add another layer of marshmallow meringue. Sprinkle meringue with a small amount of crushed graham cracker and top with a piece of Hershey's chocolate (optional) as garnish.

Serve immediately or refrigerate and serve within 24 hours.