Preheat oven to 350°F and line a standard muffin tin with paper liners.
In a large bowl sift together flour, sugar, baking powder, baking soda and salt. In a small bowl combine the melted butter, melted coconut oil, eggs, milk, vanilla and mashed banana
Pour wet ingredients into dry and mix to combine; do not over-mix.
Fold in the chopped walnuts, unsweetened coconut flakes, granola and diced banana into the batter.
Spoon batter into baking cups, filling to the top. Sprinkle each muffin with additional granola.
Bake on the center rack of the oven for 20 to 22 minutes, or until tops are brown and toothpick comes out clean when inserted in the center of the muffins.
288 calories | 17g fat, 32g carbs, 4g protein