Created by KittenCal on March 9, 2013
Step 1: Preheat oven to 350 degrees F.
Step 2: Position oven rack to second-lowest position.
Step 3: Line 14 regular size muffin tins with paper liners.
Step 4: In a medium or large bowl sift together flour with baking powder, baking soda, salt and cinnamon.
Step 5: In another bowl beat the melted butter with sugar, egg and vanilla extract until well blended (about 2 minutes) using a wooden spoon mix in the mashed bananas until just blended.
Step 6: Using a wooden spoon mix in the flour mixture until just blended (the batter will be lumpy, do not over mix).
Step 7: Gently mix in the blueberries.
Step 8: Divide the batter evenly (3/4's full) between muffin tins.
Step 9: Bake for about 22-25 minutes, or until muffins test done (if using partially thawed blueberries baking time will be slightly longer).