Preheat oven to 400 degrees F. Lightly grease a standard 12-cup muffin pan, or line with cupcake liners and grease. Set aside.
In a medium bowl, mix together 1 1/2 cups flour, baking soda, baking powder, sea salt and cinnamon, set aside.
In a large bowl, mash bananas.
Add melted butter and stir to combine.
Add eggs and vanilla and stir until mixture is homogenous (uniform throughout).
Add brown sugar and granulated sugar and stir to combine.
Add dry ingredients and stir until batter is smooth and there are no lumps (other than a few chunks of banana).
Place ¼ to 1/3 cup of batter into each well of the prepared muffin pan, smooth the tops so they are even. (Optional: add crumb topping - see notes for recipe if desired).
Bake in preheated oven for 15-17 minutes, until a toothpick inserted into center of a muffin comes out clean.
Use a spoon to immediately remove muffins from the muffin tin and transfer them to a wire rack to cool.
Optional crumb topping
¼ cup butter, softened
¼ cup brown sugar
¼ cup granulated sugar
¼ cup flour
½ tsp ground cinnamon
¼ tsp salt
Combine ingredients with a fork or pastry cutter. After filling each muffin cup with batter, place 1 1/2 TBS crumb topping on each muffin and gently press so it sticks. Bake according to recipe instructions.
All-purpose flour. bread flour or pastry flour can be used in place of all-purpose flour
Butter. Salted and unsalted butter can both be used in this banana muffin recipe. You can substitute canola or coconut oil for the butter as well.
Eggs. I have not tested this recipe with a flax egg or egg replacer, if you do let me know how it turns out please!
Brown Sugar. Light and dark brown sugar work equally well in these banana muffins. Dark brown sugar will impart a slightly more detectable molasses taste.
Granulated sugar. I use organic cane sugar in all my baking, any granulated white sugar works well.