A wonderful combination of flavors; chocolate and peanut butter. Yum! If you do not want to make the chocolate cake from scratch, you can use a chocolate box cake. This can be made into a layer cake or cupcakes, but you will have to adjust the baking time.
Grease and flour a 13x9x2 inch baking pan. Set aside.
In a large mixing bowl, beat butter, Crisco, sugar, and vanilla until light and fluffy. Add eggs. Beat well.
In another bowl, mix all the dry ingredients together; add alternately to butter mixture with milk. Blend well.
Pour batter into prepared pan and bake for 35-45 minutes until wooden tooth pick inserted in center comes out clean. Remove cake from oven and cool completely on a wire rack. Frost cake.
Peanut Butter Frosting:
In a mixer bowel, using the whisk attachment beat the butter and peanut butter for 3-5 minutes on medium to high speed. This is an important step. The butter and peanut butter must be well incorporated.
On low speed, add the powder sugar, vanilla, and cream until confectioners’ sugar is blended in. Beat on high for 2 more minutes until light and fluffy. (If mixture seems to be a tad bit crumbly, add a tiny bit more cream, but not too much. You do not want the frosting to be soft or runny. It should be light and fluffy).
OPTIONAL: Chocolate curls
Using a potato peeler, peel along the side of 1 bar of semi-sweet chocolate onto a sheet of foil. Make the curls into small pieces, or as long, short, or thick as you like. Set the foil of curls into the refrigerator to chill thoroughly. When they have chilled, sprinkle the curls over the top of the frosting.