Preheat the oven and prepare the pan

• Preheat the oven to 400 °F.
• Line the muffin tin.

Whisk the dry ingredients

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

Mix the wet ingredients

• In a separate bowl, whisk the mashed banana and brown butter until combined.
• Mix in the brown sugar and granulated sugar until smooth.
• Add the egg, greek yogurt and vanilla paste and mix until the batter is smooth.

Combine the batter

• Add the dry ingredients into the wet ingredients and gently fold until mostly combined with a few streaks of flour remaining.
• Add the finely shredded carrots and fold just until everything is incorporated, avoiding overmixing.

Fill the muffin tin

• Pour the batter into the prepared muffin pan and smooth the top.

Bake the muffins

• Bake for about 5 minutes, then reduce the temperature to 350 °F.
• Continue baking for 30 to 35 minutes, until a toothpick inserted into the center comes out clean or with just a few moist crumbs.

Cool the muffins

• Let the muffins cool in the pan for about 15 minutes.
• Transfer to a rack to cool completely before frosting.

Make the cinnamon maple frosting

• Beat the softened cream cheese and butter together until smooth and fluffy.
• Add the powdered sugar and mix until fully incorporated.
• Mix in the maple syrup, cinnamon and vanilla bean paste and continue beating until smooth and creamy.
• Adjust the texture with a little more maple syrup if too thick, or a bit more powdered sugar if too soft.

Frost the muffins

• Spread the frosting over the cooled muffins.