01 -
Preheat oven to 350°F and coat a 9×13-inch baking dish with non-stick spray.
02 -
In a large mixing bowl, whisk together the milk and chocolate instant pudding mix until smooth and slightly thickened.
03 -
Fold the chocolate cake mix into the pudding mixture and stir until just combined. Batter will be thick.
04 -
Gently fold in most of the chopped mini Reese’s peanut butter cups, reserving a portion for topping.
05 -
Transfer the batter into the prepared baking dish and spread evenly. Sprinkle the reserved peanut butter cups over the surface.
06 -
Bake for 25 minutes, or until a toothpick inserted in the center emerges clean.
07 -
Allow to cool slightly before serving warm or at room temperature.