Preheat the oven to 350ºF. Line a 12 pan muffin tin with paper liners or grease with coconut oil.

In a large bowl or mixer, combine the mashed bananas, eggs, coconut oil, vanilla extract and peanut butter until fully combined.

Add the coconut flour, cocoa powder, baking soda, baking powder, and salt to the wet ingredients and mix well. Fold in the chocolate chunks.

Divide the batter between the prepared muffin tins. Add a dollop of peanut butter to the top of the muffin and swirl in with a knife of toothpick.

Bake in the preheated oven for about 16-19 minutes. A toothpick inserted into the center of a muffin should come out clean.

Remove from oven and allow to cool on a wire rack for about 10 minutes. Flip out onto a cooling rack to finish cooling.