Banana Chocolate Chip Granola Muffins

for the muffins:
1 1/2 cups flour
1 tsp baking powder
1 tsp baking soda
1/2 tsp salt
2 ripe medium bananas, mashed
3/4 cup sugar
1 egg
1/3 cup butter, melted
1 1/2 cups chocolate chunk granola (I used Back to Nature and it was delicious!)
1/2 cup mini chocolate chips
turbinado sugar, if desired

for the granola topping:
2 tbsp flour
1/3 cup brown sugar
1/8 tsp cinnamon
2 1/2 tbsp butter, melted
1/2 cup granola

Preheat oven to 375.
Whisk together the flour, baking powder, baking soda, and salt in a large bowl and set aside.
In a separate bowl, beat together the bananas, sugar, egg and butter until fully combined.
Gradually stir the banana mixture into the flour mixture.
Stir in the granola and the chocolate chips.
Line a muffin tin with baking cups, and fill with the batter and set aside.
In a small bowl, combine the flour, brown sugar, cinnamon, melted butter, and granola.
Top the muffins with the granola topping (or a sprinkle of turbinado sugar, if desired).
Bake for 18-20 minutes, or until a toothpick inserted in the center of a muffin comes out clean.
Cool in the pan for about 5 minutes, then transfer to a wire rack to cool completely.