Preheat oven to 350F. Spray muffin pan with nonstick spray.
In a mixing bowl, combine:
3 large mashed bananas (the riper the better)
1/4 cup brown sugar
1/2 cup white sugar
1/3 cup softened butter
1 tsp vanilla
2 tsp cinnamon
In another bowl, sift together and then add all at once to wet mixture:
1 1/2 c flour
1 tsp baking powder
1 tsp soda
1/2 tsp salt.
Fold in dry ingredients. Do not overmix.
Fill muffin tin (should make about 12 large muffins).
In a small bowl, combine until crumbly:
1/4 cup butter (not too soft)
2/3 cup flour
3 Tbs brown sugar
1 tsp cinnamon
Sprinkle crumb mixture on muffins.
Bake at 350F for about 25 minutes.
Tip: These muffins freeze very well and make for a great fast breakfast. To freeze: cool muffins completely then wrap each one in plastic wrap. Place all muffins in a gallon sized freezer bag and freeze. Reheat individual muffins for 30-45 seconds.