Preheat oven to 400F degrees. Grease 24 regular size muffin cups and set aside. In a medium bowl combine the flour, 2/3 cup sugar, baking powder, and salt. Set aside.
In a separate bowl, combine egg, milk, oil, and mashed bananas. Make a well in the dry mixture and add the wet mixture all at once. Stir just until combined.
Fold in the 2 cups of cranberries.
Spoon batter into prepared muffin cups filling each one 2/3s full. Lightly sprinkle with the cinnamon and sugar mix. Bake for 18-20 minutes until a toothpick inserted in the center comes out clean. Cool muffin cups on a wire rack for 5 minutes and then remove from baking tin.