Weekend recipe - Banana muffins

I'm trying to stretch the blueberries to last until June, when I can harvest some more, so I switched to banana muffins this week.  I was disappointed in the recipe.  The flavor was good, but the visual appeal was not.  They turned out too grey for muffins.  Muffins should be a nice tan/brown color.

I think this is similar to the problem I had with my blueberry muffins in the fall.  I was using baking soda instead of baking powder.  So, the next version I try will be a baking powder based recipe.

Below is the recipe I tried this weekend:

Preheat the oven to 350, and grease muffin tins for 12

1-1/2 Cups flour
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
1 teaspoon cinnamon
1/4 teaspoon nutmeg

3 large bananas, well-ripened
3/4 Cup white sugar
1 egg
1/3 Cup melted butter
1/4 teaspoon vanilla

Mix the dry ingredients in a large bowl, mix the wet ingredients in a small bowl.  Gently mix the wet ingredients into the dry until everything is incorporated.

Spoon into prepared muffin tins

Bake 25-30 minutes

Here is the result: