Preheat oven to 400°. Sprinkle berries with sugar; toss lightly to coat; set aside.
In a large bowl, beat egg; add yogurt and melted butter or margarine; beat until smooth; add baking mix; stir until just blended; fold in berries and lemon zest.
Spoon mixture into greased or sprayed muffin cups, 3 inch in diameter and 1-1/2 inch deep.
Bake for 20-25 minutes, or until a toothpick inserted in the center comes out clean. Cool for 5 minutes in cups; finish cooling on rack.
