Rhubarb Coffee Cake

2 cups whole wheat pastry flour
2 teaspoons baking powder
¼ teaspoon sea salt
½ cup butter, softened
¾ cup cane sugar
1 egg
1 teaspoon vanilla extract
½ cup milk
2 cups chopped rhubarb
2 tablespoons sugar

Topping
1/4 cup cold butter, cubed
½ cup whole wheat pastry or all-purpose flour
½ cup brown sugar

1. Spray an 8×8-inch baking pan with cooking spray. In a medium bowl combine the flour, baking powder, and salt.
2. In the bowl of a stand mixer, beat the butter and sugar together using the paddle attachment until light and fluffy. Add the egg and vanilla and beat well. Add flour mixture and milk alternately, and beat until smooth.
3. Spoon batter into prepared pan. It will be very thick, almost like cookie dough. Sprinkle with the chopped rhubarb and 2 tablespoons sugar.
4. Heat oven to 350°F. In another bowl add the topping ingredients. Cut butter into flour and sugar using a fork or pastry cutter until mixture resembles coarse crumbs. Stir in 2 tablespoons cold water and sprinkle mixture over rhubarb. Bake for 50 to 55 minutes or until golden. Serve warm. Makes 16 smaller servings or 9 large servings. Best eaten the same day you bake it.