For the cupcakes:
- 1 box chocolate fudge cake mix
- 3 large eggs
- 1/2 cup vegetable oil
- 3/4 cup whole milk
- 1 cup sour cream
- 1 teaspoon vanilla extract
- 1 cup Oreo crumbs
- 1 cup mini chocolate chips
For the chocolate Oreo buttercream:
- 1 cup salted butter, softened
- 3 1/2 cups powdered sugar
- 3/4 cup cocoa powder
- 3 to 5 tablespoons heavy cream
- 1 teaspoon vanilla extract
- 1 1/4 cups Oreo crumbs
For the topping: