In a mixing bowl, pour melted the butter. Mash in the bananas using a potato masher or wooden spoon. Stir in the sugar, vanilla, eggs and juice until well combined.
Sprinkle the baking soda, baking powder and salt over the top, stir in. Mix in 1¼ cups of flour, cinnamon and ginger and then stir until combined. Batter will be lumpy.
Toss the remaining ¼ cup flour with the blueberries and fold into the batter. Spray a jumbo muffin pan with cooking spray, or line with liners if desired. Use an ice cream scoop to fill the muffin cups ¾ full.
Bake for 25-30 minutes, until a toothpick inserted comes out clean and the muffin tops are golden brown. Let cool slightly before removing from pan.