- 1 1/4 cups 1¼ cups creamy or crunchy peanut butter
- 3 tablespoons ground flaxseed
- 2 teapoons baking soda
- 1 teaspoon baking powder
- Pinch salt
- 2 large ripe bananas, mashed, plus ½ banana sliced, for topping
- Make the cupcakes: Heat oven to 350° F. Line a standard 12-cup muffin tin with paper liners. In a medium bowl, whisk together the flour, baking powder, and salt; set aside.
- Using an electric mixer, beat the butter and sugar on medium-high until fluffy, 2 to 3 minutes. Beat in the eggs, one at a time, then the vanilla, scraping down the sides of the bowl as necessary.
- Reduce mixer speed to low. Add the flour mixture in 3 additions and the coconut milk in 2 additions, beginning and ending with the flour mixture. Mix just until combined (do not overmix).
- Divide the batter evenly among the muffin cups. Bake until a toothpick inserted in the center comes out clean, 15 to 20 minutes. Cool in the tin for 10 minutes, then transfer to a rack to cool completely.
- Make the frosting: Using an electric mixer, beat the butter, sugar, coconut milk, vanilla, and salt on high until light and fluffy, 3 to 5 minutes, scraping down the sides of the bowl as necessary. Frost the cupcakes and sprinkle with the toasted coconut.