Preheat oven to 375 degrees F. Prepare muffin tins with liners.
In a large bowl, add flour, cocoa, baking powder, salt, chile powder and cayenne. Sift together to combine. Set aside.
3 cups (375 g) all-purpose flour, 2/3 cup (64 g) unsweetened cocoa, 1-1/2 tsps. (7 g) baking powder, 1/2 tsp. (3 g) table salt, 1 tbsp. chile powder, 1-3/4 tsps. cayenne pepper
In the bowl of a stand mixer, add sugar, eggs and bananas. Blend until thoroughly combined. Add flour mixture alternating with buttermilk and ending with flour. Mix just until combined. Fold in chocolate chips.
2 cups (400 g) granulated sugar, 2 large eggs, 4 medium ripe bananas, 1/2 cup (118 ml) buttermilk, 1 cup (180 g) semi-sweet chocolate chips
Add 1/4 cup batter to each muffin liner and top each muffin with bittersweet chocolate chunks (8 to each muffin) and bake for 25 minutes or until done.
bittersweet chocolate chunks
Cool for five minutes in the pan and remove to a wire rack to cool completely.