- 1 1/2 cups unbleached or all-purpose flour
- 1 teaspoon baking soda
- 1/4 teaspoon salt
- 1/2 cup sugar
- 1 large egg
- 1 cup fat-free plain yogurt
- 2 tablespoons vegetable oil
- 1 tablespoon vanilla extract
- 1 cup fresh or frozen blueberries
- 1/2 cup unbleached or all-purpose flour
- 1/4 cup sugar
- 2 tablespoons butter or margarine, softened
- 1 teaspoon ground cinnamon
- To make the cake: Preheat the oven to 350 degrees F (180 degrees C). Coat an 8 inch x 8 inch (20 x 20-cm) baking dish with nonstick spray.
- In a large bowl, combine flour, baking soda, salt, and sugar.
- In a medium bowl, combine egg, yogurt, oil, and vanilla extract. Stir egg mixture into flour mixture, just until moist. Stir in blueberries. Spoon batter into the prepared baking dish.
- To make the topping: In a small bowl, using a fork, combine flour, sugar, butter or margarine, and cinnamon until mixture resembles coarse crumbs. Sprinkle over cake. Bake 40 to 45 minutes, or until a wooden pick inserted into the center comes out clean.