I usually don't use mixes, but I like this recipe. It came from a Duncan Hines book, but I used Krusteaz fat-free mix even though I only had one piece before giving it away. It tastes really good and I doubt anyone can tell it was fat-free except the topping.
Spring Break Blueberry Coffee Cake
1/2 c. flaked coconut
1/4 c. firmly packed brown sugar
2 T. butter or margarine softened
1 T. flour
1 package blueberry muffin mix
1 (8-oz.) can crushed pineapple with juice
1/4 c. water
Preheat oven to 350 degrees. Grease 9 inch square pan.
FOR TOPPING: Combine coconut, brown sugar, butter and flour in small bowl. Mix with fork until well blended. Set aside.
Preheat oven to 350º. Rinse blueberries from mix with cold water and drain. Empty muffin mix into medium bowl. Break up any lumps. Add pineapple with juice, egg and water. Stir until moistened, about 50 strokes. Fold in blueberries. Spread in pan. Sprinkle reserved topping over batter.
Bake for 30-35 minutes or until toothpick inserted in center comes out clean. Serve warm or cool completely.