Preparation / Directions:
Preheat the oven to 350 degrees. Butter and flour an 11 to 12 inch round baking dish.
Streusel: Combine all ingredients in a bowl and work with a pastry blender or your fingers until the mixture forms crumbs.
Batter: Sift together the flour, baking powder, salt and cloves. In an electric mixer, cream the butter and sugar until light and fluffy. Beat in the yolks one at a time, followed by the milk and zest.
Final assembly: Using a clean bowl and beaters, beat the egg whites with the sugar and salt to form medium peaks. Stir the flour mixture into the butter yolk mixture. Fold in the egg whites with half of the blueberries. Transfer the batter to the prepared baking dish and sprinkle it with the steusel. Top with the remaining blueberries.
Bake until the cake is set on top -- 40 to 45 minutes. Remove from the oven and let it sit for 30 minutes. Serve warm.