Cinnamon Swirl Banana Bread

My co workers gave this rave reviews when I took it into the office last week!  Delicious swirls of cinnamon make this the best banana bread you've ever had.  Use ripe (not over-ripe) bananas and bake in a glass bread pan for best results.  My co workers gave this rave reviews last week when I took it into the office!

1 1/2 c all purpose flour
1 1/4 tsp baking powder
1/2 tsp baking soda
1/2 tsp cinnamon
1/8 tsp salt

1 egg, slightly beaten
1 c mashed banana
3/4 c sugar
1/4 c oil

Swirl Mixture:
3 Tbsp sugar
1 1/2 tsp cinnamon
2 1/2 Tbsp margarine

Preheat oven to 350.  In a medium mixing bowl, stir together flour, baking powder, baking soda, cinnamon and salt.  In a large mixing bowl, stir together egg, banana, sugar, and oil.  Stir flour mixture into banana mixture just until moistened.  Spray and 8x4 inch loaf pan with nonstick spray.  Spread batter in prepared pan.  Combine Swirl Mixture and microwave for 15-20 seconds, stir.  Spoon mixture over top of batter.  Use toothpick to create marble effect. 

Bake for 45 to 50 minutes.  Cool bread for 10 minutes in pan, then cool on wire rack.