1/2 c. firmly packed brown sugar
1/2 c. rolled oats
2 tsp. ground cinnamon
1/4 c. (1/2 stick) chilled butter
3 c. all-purpose flour
1 1/2 tsp. baking powder
1 1/2 tsp. baking soda
1/2 tsp. ground nutmeg
3/4 c. (1 1/2 sticks) unsalted butter, room temperature
1 1/3 c. sugar
3 eggs
1 tsp. vanilla extract
1 1/2 c. plain yogurt
1 med. apple, peeled, cored & chopped

Preheat oven to 350 degrees. Grease two 9 x 5 x 3 inch loaf pans. Combine first 3 ingredients in small bowl. Cut in 1/4 cup chilled butter using fingers or pastry blender until mixture resembles coarse meal. Set streusel mixture aside.

Sift flour, baking powder, baking soda and nutmeg into large bowl. Using electric mixer, cream 3/4 cup butter and 1 1/3 cups sugar together in another large bowl until fluffy. Add eggs, one at a time, beating well after each addition. Mix in vanilla. Fold in dry ingredients alternately with plain yogurt, beginning and ending with dry ingredients.

Pour about 1 1/2 cups batter into bottom of each prepared pan. Sprinkle 1/3 cup streusel over each. Sprinkle 1/4 of apple over each. Divide remaining batter, streusel and apple between pans, beginning with batter. Run small sharp knife through batter to create swirl. Bake until golden brown and toothpick inserted into center comes out clean, about 55 minutes. Cool on rack. Serve warm or at room temperature.