This Peanut Butter Cup Earthquake Cake recipe is made with Reese's, peanut butter frosting made from scratch as a rich filling, and chocolate cake mix – great dessert idea! Tastes just like the popular candy, but in the best cake.
In a large bowl, mix together cake mix, eggs, 1 cup milk, 1 cup of peanut butter, and 1 stick of butter. Spread mixture in a greased 9x13" baking dish.
With a mixer, mix together 1 stick butter, 1 cup peanut butter, and 1/4 cup milk. Slowly add in powdered sugar until frosting is mixed well.
Spoon half of the frosting mixture on top of the cake mix. Add 6-8 large squirts of chocolate syrup.Very gently swirl frosting and syrup into the cake mix. Don't completely mix. Make sure you get swirls into the edge of the cake pan.
Gently press in half of the chopped peanut butter cups.
Bake cake for 35-40 minutes at 350 degrees.Top cake with remaining frosting, more chocolate syrup, and remaining chopped peanut butter cups.