1 egg
2 c. Bisquick
1 1/4 c. mashed bananas (2 med.)
1/3 c. sugar
3 tbsp. oil

Grease 12 muffin cups. Beat egg slightly; stir in remaining ingredients. Fill muffin cups 1/4 full and sprinkle with the following filling:

1/3 c. chopped walnuts
3 tbsp. brown sugar

Put remaining batter over filling. Bake at 400 degrees for about 15 minutes.