Blueberry Coffee Cake

from Simply in Season cookbook

1 cup flour
1/2 cup whole wheat flour
1/2 cup sugar
1 tablespoon baking powder
1 teaspoon ground cinnamon
1/2 teaspoon salt
Mix, then gently fold in
1 1/2 cups blueberries
1 tsp lemon zest (optional)

1 egg
1/2 cup milk
1/4 cup melted butter or oil
Whisk together, add to flour mixture. Batter will be stiff.

Topping:
1/3 cup sugar
1/3 cup whole wheat flour
1/3 cup walnuts or other nuts
2 tablespoons butter
1 tsp cinnamon
Mix until crumbly and sprinkle over top.

Bake at 425 until light golden brown, about 20-25 minutes. Serve warm or at room temperature, try with warm milk poured on top.