Preheat oven to 350°F.

Prepare a cookie sheet with nonstick pan spray or line with a sheet of parchment paper.

In a stand mixer or using a hand electric mixer, cream butter and sugar until lighter in color and fluffy, about 2-3 minutes.

Add eggs, one at a time, until fully incorporated.

In a separate bowl, whisk the flour, baking soda, salt, pumpkin spice and cinnamon together.

Add the pumpkin puree and 1/2 the flour mixture to the butter mixture. Mix only until mostly blended. Add remaining flour mixture. Blend only until dry ingredients are no longer visible. Do not over mix.

Carefully pour batter onto prepared cookie sheet. The mixture will be thick but spreadable. Using a spatula, evenly spread the batter on the cookie sheet.

Bake at 350°F for about 30 minutes or until a toothpick in the center comes out clean with minimal crumbs.

Let the cake cool completely before frosting.

In a stand mixer or using a hand electric mixer, beat together the butter and cream cheese until smooth.

Add vanilla, powdered sugar and pumpkin spice. Beat until fully combined. Scrape sides of mixing bowl to ensure even mixing.

Spread a thin layer of frosting over cooled cake.

Sprinkle cinnamon or pumpkin spice over frosting as a garnish if desired.