Sprinkle fruit with 1/3 cup sugar, let stand 1 hour.
Heat oven to 425 F. Mix baking mix, milk, 3 tablespoons sugar and the margarine until soft dough firms mix. Knead 8 to 10 times. Roll dough 1/2 inch thick.
Smooth dough into ball on cloth covered board lightly floured with baking
Cut with floured 3-inch cutter.
Bake on ungreased cookie sheet until golden brown, 10 to 12 minutes.
Mix sour cream and brown sugar. Split shortcakes; fill and top with fruit.
Top with sour cream.