Chocolate Sheet Cake with Peanut Butter Frosting

Step 1: To make the sheet cake: Preheat oven to 350 degrees. Grease a 11 x 7 jelly roll pan sheet pan.

Step 2: In a large mixing bowl, whisk together sugar, flour, baking soda, and salt. In a separate bowl, whisk together eggs, buttermilk, and vanilla extract. Set aside.

Step 3: In a small sauce pan, melt the butter on medium-low heat. Whisk in the cocoa powder and hot water. Turn up the heat to medium-high and bring the mixture to a boil. Add the melted butter mixture to the dry ingredients and mix until smooth. Stir in the egg mixture and mix until ingredients are combined.

Step 4: Pour the batter into the prepared sheet pan and tap on the counter a few times to distribute the cake batter evenly. Bake the cake for 18 minutes, or until a toothpick comes out clean when inserted in the center.

Step 5: Meanwhile while the cake is baking, make the peanut butter frosting. In a bowl combine the sifted powdered sugar, milk or cream peanut butter, and vanilla extract. Beat until smooth. Frost the chocolate sheet cake as soon as you remove it from the oven (the peanut butter frosting will spread easily over the warm cake). Sprinkle chopped Reese's Peanut Butter Cups over the frosting, if desired.

Step 6: Allow the frosted cake cool to room temperature. Cut into squares and serve.