1. Preheat oven to 350°F. Lightly grease a 9- or 10-inch cast-iron skillet. In a large bowl stir together flour, sugar, baking powder, and baking soda. Using a pastry blender, cut in butter until mixture resembles coarse crumbs. Make a well in center of flour mixture.

2. In a small bowl combine egg, buttermilk, and vanilla. Add egg mixture all at once to flour mixture. Stir just until moistened (batter should be slightly lumpy). Spread half of the batter into prepared skillet. Sprinkle with 3/4 cup of the Streusel. Drop remaining batter in small mounds onto layers in skillet; sprinkle with remaining streusel.

3. Bake 30 to 40 minutes or until golden and a toothpick comes out clean. Cool in skillet on a wire rack 30 minutes. If desired, drizzle with Powdered Sugar Icing and sprinkle with raspberries. Serve warm.

Streusel

In a medium bowl stir together 1/2 cup each packed brown sugar and all-purpose flour and 1 tsp. ground cinnamon. Cut in 1/4 cup butter until mixture resembles coarse crumbs.

Powdered Sugar Icing

In a small bowl stir together 1 1/4 cups powdered sugar, 1 Tbsp. milk, and 1/2 tsp. vanilla. Stir in additional milk, 1 tsp. at a time, to reach drizzling consistency.

*Tip

To make 3/4 cup sour milk, place 2 tsp. lemon juice or vinegar in a glass measuring cup. Add enough milk to make 3/4 cup total liquid; stir. Let stand 5 minutes before using.