Sift flour, soda and baking powder together.
Cream sugar and margarine together
and beat in eggs. Add 1/4 of flour mixture
and 1/3 of sour cream; continue to alternate
and cream until blended. Add vanilla.
Grease and flour loaf pan.

Filling: 1 tbs. cocoa
2 tbs. sugar
1 tbs. instant coffee
Combine ingredients, pour 1/3 batter into pan.
Sprinkle 1/2 filling over batter.
Add another 1/3 batter and remaining filling.
Cover with remaining batter.
Marble with knife.
Bake at 350F for 45-50 min.
Dust with powdered sugar when cool.
12 servings.