TOPPING:

1/3 c. firmly packed brown sugar
1 tsp. ground cinnamon
1/2 c. chopped nuts
1/3 c. unsifted all-purpose flour
2 tbsp. butter

1/4 c. butter
2 lg. eggs
1 tsp. grated lemon peel
1 tsp. baking powder
1 c. sour cream
1 c. granulated sugar
1 tsp. vanilla extract
2 c. unsifted all-purpose flour
1/2 tsp. baking soda
1 1/2 c. fresh or frozen blueberries

1. Make topping: In small bowl, combine brown sugar, 1/3 cup flour and the cinnamon; mix well. With two knives, cut in 2 tablespoons butter until mixture resembles coarse crumbs; stir in nuts; set aside.

2. In large bowl, with electric mixer at medium speed, cream butter and sugar until light; beat in eggs, vanilla and lemon peel. At low speed, beat in flour, baking powder, soda and sour cream; gently stir in blueberries.

3. Grease a microwave-safe shallow, 10 inch round baking dish; spoon in batter. Sprinkle with topping. Cook on HIGH 10 minutes, rotating dish a quarter turn every 2 minutes, or until cake tester inserted in center comes out clean. Let stand 10 minutes. Serve warm or at room temperature. Garnish with additional blueberries and lemon peel, if desired.

Makes 8 servings.