1. Preheat the oven to 350°F and grease two 8-inch round cake pans. Line the bottoms with parchment if desired.

2. In a medium bowl, whisk together the flour, baking powder, and salt.

3. In a large bowl, beat the butter, peanut butter, and granulated sugar until light and fluffy.

4. Add the eggs one at a time, mixing well after each addition, then mix in the vanilla extract.

5. Add the dry ingredients in three additions, alternating with the milk, beginning and ending with the dry ingredients. Mix just until combined.

6. Divide the batter evenly between the prepared pans and smooth the tops.

7. Bake for 25 to 32 minutes, or until a toothpick inserted in the center comes out with a few crumbs.

8. Cool the cakes in the pans for 10 minutes, then transfer to a wire rack and cool completely.

9. For the frosting, beat the butter and peanut butter until smooth. Add the powdered sugar gradually, then mix in the vanilla and enough heavy cream to make a fluffy spreadable frosting.

10. Place one cake layer on a plate, spread frosting over the top, add the second layer, and frost the top and sides.

11. Finish with peanut butter chips and mini chocolate chips, then slice and serve.