Well-chopped rhubarb offers bursts of tartness in this moist, spicy coffee cake.
3 1/2 cups finely chopped rhubarb (about 1 pound)
2 tablespoons all-purpose flour
1 1/2 cups packed brown sugar
5 tablespoons butter, softened
2 large eggs
1 cup fat-free sour cream
1 teaspoon grated orange rind
2 teaspoons vanilla extract
1 1/2 cups all-purpose flour (about 6 3/4 ounces)
1 cup whole wheat flour (about 4 3/4 ounces)
1 teaspoon baking soda
1 teaspoon ground cinnamon
1/2 teaspoon salt
1/4 cup turbinado sugar
1/2 teaspoon ground cinnamon
2 tablespoons chilled butter, cut into small pieces
1/4 cup chopped walnuts
How to Make It
Preheat oven to 375°.
To prepare cake, combine rhubarb and 2 tablespoons flour in a medium bowl; toss well to coat.
Place brown sugar and 5 tablespoons butter in a large bowl; beat with a mixer at medium speed until light and fluffy. Add eggs, 1 at a time, beating well after each addition. Add sour cream, rind, and vanilla; beat until well combined.
Lightly spoon 1 1/2 cups all-purpose flour and whole wheat flour into dry measuring cups; level with a knife. Combine flours, baking soda, 1 teaspoon cinnamon, and salt, stirring with a whisk. Gradually add flour mixture to butter mixture, beating at low speed just until combined. Fold in rhubarb mixture. Spread batter into a 9-inch square baking pan coated with cooking spray.
To prepare streusel, combine turbinado sugar and 1/2 teaspoon cinnamon in a small bowl. Cut in 2 tablespoons butter with a pastry blender or 2 forks until mixture is crumbly; stir in nuts. Sprinkle streusel evenly over batter. Bake at 375° for 50 minutes or until a wooden pick inserted in the center comes out clean.