Preheat oven to 350 degrees Fahrenheit. Line a muffin tin with 12 cups with paper liners or grease with cooking spray.
In a large bowl, whisk together gluten-free flour, sugar, cocoa powder, baking soda, salt and baking powder.
In a medium sized bowl, add mashed bananas, vegetable oil, vanilla, and apple cider vinegar and stir until thoroughly combined.
Then, add the banana mixture into the dry ingredients. Stir until the mixture is moist and there are no more streaks of the dry ingredients. Fold in the chocolate chunks and chips.
With an ice cream scoop or spoon, fill the greased or lined muffin cups with the batter.
Bake in the oven for 20-25 minutes or until a toothpick inserted in the middle of the muffin comes out clean.