Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or grease the cups.

In a large bowl, combine the mashed bananas, melted butter, granulated sugar, brown sugar, and egg.

Mix until well combined.

In a separate bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon.

Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Be careful not to overmix.

Gently fold in the fresh raspberries, being careful not to crush them too much.

Spoon the batter into the muffin cups, filling each about two-thirds full.

Bake in the preheated oven for 18-20 minutes or until a toothpick inserted into the center comes out clean.

Allow the muffins to cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.