Preheat the oven to 375°F. Line two 12-cup muffin tins with paper liners or grease the cups.
In a large bowl, mash the bananas.
4 medium ripe bananas
Mix in the butter, sugars, and egg and beat to combine.
1 cup unsalted butter, 1 cup granulated sugar, ½ cup brown sugar, 2 large eggs
In a seperate bowl, whisk together the dry ingredients.
3 cups all-purpose flour, 2 teaspoons baking soda, 1 teaspoon baking powder, 1 teaspoon salt, 1 teaspoon ground cinnamon
Add the dry ingredients to the wet ingredients a little bit at a time. Once the dry ingrdients are incorporated stop mixing.
Use a rubber spatula to gently fold the raspberries into the batter. Take care not to crush the berries.
2 cups fresh raspberries
Use a large spoon or cookie scoop to portion out the muffin batter into the pans. Take care to fill them two-thirds full.
Bake for 18-20 minutes until the muffins are golden brown and a toothpick inserted in the center comes out clean.
Remove from the oven and let rest 5 minutes before moving them to a wire baking rack to cool completely.