If you love chocolate and peanut butter together, you will love this Peanut Butter Cup Cake. It's Triple Chocolate Cake topped with Peanut Butter Cream Cheese Frosting filled and decorated with mini Reese's Peanut Butter Cups. Yum!
Take the butter and cream cheese out of the refrigerator to soften.
Butter and flour 2-8" round cake pans, set aside.
Preheat oven to 350° F.
In a mixing bowl, beat together the cake mix, water, oil, and eggs until thoroughly combined.
Pour evenly into the prepared pans.
Place in oven and bake for 30-34 minutes.
Remove cake from oven when cooked.
Cool in pan for 10 minutes, then remove from pan and cool completely on racks before assembling.
In a stand mixer with a paddle attachment on medium speed, cream the butter and cream cheese until smooth, about 2-3 minutes.
Add the confectioner's sugar in gradually, mixing in between pours. Once it is all added, increase speed and beat until smooth.
Add in the vanilla and salt as you continue to mix.
Add the peanut butter and mix until completely combined.
Use immediately or refrigerate for up to 4 days.
Remove the foil from the peanut butter cups.
Using a butcher's knife, chop up half of the peanut butter cups into smaller pieces for the filling.
Place the bottom layer on your cake board or platter.
Use a bread knife or cake leveler to even out the top of the cake.
Frost the cake with the frosting.
Add the layer of chopped up peanut butter cups on top.
Place the top layer on top of the peanut butter cups.
Frost this layer, filling in the gaps between the cakes.
Decorate the top with whole miniature Reese's Cups.
Store in the refrigerator until serving.