Preheat oven to 400F. Lightly coat bottoms of twelve 2-1/2-inch muffin cups with cooking spray; set aside. In a large bowl combine flour, millet, baking powder and salt. Make a well in the center of the flour mixture; set aside.
In a medium bowl whisk together milk, oil, eggs, applesauce, brown sugar, granulated sugar and vanilla. Add to flour mixture all at once. Stir just until moistened (batter should be lumpy). Fold in bananas.
Spoon batter into prepared muffin cups, filing each two-thirds full. Bake for 15 to 18 minutes or until golden and a wooden toothpick inserted near the center comes out clean. Cool in muffin cups on a wire rack for 5 minutes. Remove from muffin cups; serve warm.