Heat oven to 350
In large mixer bowl combine sugar, margarine, buttermilk,
eggs, vanilla. Beat at medium speed, scraping bowl often,
until creamy (1 to 2 minutes) add bananas; continue beating
until well mixed (1 minute).
Add flour, baking soda and salt. Beat at low speed until
moistened (1 to 2 minutes). By hand, stir in blueberries,
spoon into paper-lined muffin cups, filling each 2/3 full.
Bake for 25 to 30 minutes, or until toothpick inserted in
center comes out clean. Remove from pan. Cool. Just before
serving, sprinkle tops of cakes with powdered sugar.
This makes 20 snack cakes.