Preheat the oven

• Preheat the oven to 218 °C.
• Line a muffin pan with muffin liners.

Mix the dry ingredients

• In a bowl, whisk together the flour, baking soda, baking powder, salt and cinnamon until evenly combined.

Whisk the wet ingredients

• In a separate bowl, whisk the mashed bananas and melted butter until smooth.
• Add the granulated sugar and brown sugar and mix until glossy.
• Whisk in the eggs, buttermilk and vanilla until fully combined.

Combine and fold in the chocolate chips

• Add the dry ingredients to the wet ingredients and gently fold until mostly combined, with a few streaks of flour remaining.
• Fold in the mini chocolate chips just until incorporated, avoiding overmixing so the muffins stay soft and fluffy.

Rest the batter

• Let the batter rest so the flour hydrates and the muffins get taller tops.

Fill the muffin pan

• Fill the muffin liners almost to the top.
• Sprinkle the tops with mini chocolate chips.

Bake the muffins

• Bake for 5 minutes at 218 °C.
• Reduce the oven temperature to 175 °C and bake another 13–15 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs.

Cool and serve

• Let the muffins cool slightly in the pan, then enjoy.