Preheat the Oven: Set your oven to 350°F (175°C). Grease a 9×13-inch baking dish to prevent sticking.
Layer the Peanut Butter Cups: Spread chopped peanut butter cups evenly across the bottom of the dish.
Add the Cake Mix: Sprinkle the dry chocolate cake mix evenly over the peanut butter cups – no mixing required!
Drizzle with Peanut Butter & Milk: Warm the peanut butter slightly to make it easier to pour, then drizzle it over the cake mix. Add the milk for extra moisture.
Top with Butter: Scatter slices of butter across the surface to create a rich, golden topping.
Bake to Perfection: Bake for 35-40 minutes, or until the top is golden brown and the edges are bubbly.
Serve and Enjoy: Let the cake cool slightly before serving. For the ultimate treat, top with a scoop of vanilla ice cream or a drizzle of chocolate syrup.