Chocolate Peanut Butter Earthquake Cake

Preheat oven to 350°F and grease a 9×13-inch baking dish.
Prepare cake mix according to package instructions and pour into the baking dish.
In a separate bowl, blend cream cheese, butter, peanut butter, and vanilla until smooth. Gradually mix in powdered sugar.
Drop spoonfuls of the peanut butter mixture onto the cake batter and spread lightly with a spatula.
Sprinkle chocolate chips and peanut butter cups evenly over the top.
Bake for 45-50 minutes, or until a toothpick inserted in the center comes out clean.
Serve warm, with a scoop of ice cream if desired.