Preheat oven to 350 degrees F (177 degrees C). Place the oven rack in the center of the oven.
Line a 12 cup muffin pan with paper liners.
In a small saucepan melt the butter. Let cool to room temperature.
In a medium sized bowl whisk mashed banana, melted butter/oil, salt and sugar.
In another large bowl sift flour,baking powder, baking soda, cinnamon, and salt.
Add the wet ingredients to the dry ingredients and stir only until the ingredients are just combined.
Do not over mix the batter or tough muffins will result.
Divide the batter evenly among the 12 muffin cups, using two spoons or an ice cream scoop. Place in
the oven and bake until a tester inserted in the center of a muffin comes out clean, about 20 to 25
minutes. Transfer to a wire rack to cool.