• Preheat the oven to 325 degrees F, grease and flour a 9x13 sheet cake pan. We also like to line the bottom of the pan with parchment.
• In a separate bowl, add the flour, sifted cocoa, baking soda, baking powder and salt. Whisk to blend and set aside.
• In another bowl, combine the one cup sour cream, vanilla extract, vegetable oil, and milk and set aside. (not the coffee yet).
• In the bowl of your mixer, beat the softened butter on medium speed until smooth.
• Gradually add the sugar and mix on medium speed until light and fluffy, approximately 4 to 5 minutes. (Stop and scrape down the sides of the bowl with a spatula as needed.)
• Add the eggs one at a time, mixing after each egg just until the yellow of the yolk has blended. Scrape down the sides and bottom of the bowl as needed.
• Mixing on low speed, alternately add the flour mixture and sour cream mixture to the sugar mixture, beginning and ending with the dry ingredients. (3 additions of dry ingredients and 2 additions of milk) Mix just until combined.
• With mixer on low speed, slowly pour in the hot coffee. We used instant espresso dissolved into very hot water but any hot coffee will do. If you don't want to use coffee, you can use hot water instead.
• Gently fold in the mini chocolate chips and scoop the batter into the prepared 9x13 sheet cake pan. Bake at 325 for 35-40 minutes-- a toothpick should come out clean or with just a few crumbs attached. *Baking times may vary. Then, remove from the oven and place on a wire rack for 5-10 minutes before turning out.
• Allow to cool completely before frosting the cake.

Peanut Butter Frosting

• In the bowl of your mixer add the softened butter and mix on medium speed until the butter is smooth. Add the peanut butter and mix until blended.
• Gradually add the powdered sugar alternately with the milk. Add vanilla. Mix on medium speed 4 to 5 minutes until smooth.

Chocolate Glaze (optional)

• Combine the 4 oz. semi-sweet or dark chocolate and 3 oz. heavy cream in a microwave safe bowl.
• Heat in the microwave in small increments (30 seconds or less), stirring occasionally in between, until the chocolate is almost completely melted. Then, allow to sit a minute or two and gently stir to melt any remaining pieces of chocolate.
• Cool the ganache/glaze to desired consistency for spreading onto the top of the cake. This may take several minutes, or you can speed it up by refrigerating for just a few minutes. We used ours when it was easily spreadable and soft but not runny. It should be cool/room temp as you don't want to melt your frosting when you apply it to the cake.

Assembly & Decorating

• Once the cake has cooled completely, it is time to frost with peanut butter frosting! I like to do a thin "crumb coat" of frosting on the top and sides of the cake, chill in the freezer (or longer in the refrigerator) for about 15 minutes, and then add the second coat of frosting.
• Decorate however you like! I frosted the the cake smooth with an offset spatula, and then piped a chunky shell/braided border using a large star (1M) piping tip. I spread some cooled (but still very soft) ganache on top. I used sliced Reese's Cups to create a bottom border and also added some on top.

Storage

• This cake is fine at room temperature for a couple of days in an airtight container, or sealed cake box. Beyond that, we recommend moving to the refrigerator for freshness. **Just as with any of our cakes, chilled cakes are more firm. If you chill the cake, you should remove from the refrigerator a few hours before serving so that it can warm and soften.