Ingredients

  • 1/4 cup all purpose flour
  • 1/4 cup (packed) golden brown sugar
  • 3 tablespoons unsalted butter, room temperature
  • 1/2 teaspoon ground cinnamon
  • Nonstick vegetable oil spray
  • 1 1/2 cups all purpose flour
  • 1/4 cup (packed) golden brown sugar
  • 2 teaspoons baking powder
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1/2 cup unsweetened applesauce
  • 1/3 cup low-fat buttermilk
  • 2 tablespoons vegetable oil
  • 1 large egg yolk
  • 1 teaspoon vanilla extract
  • 1/2 teaspoon (packed) grated lemon peel
  • 2 large egg whites

Method

  • Preheat oven to 350F.
  • Combine all ingredients in small bowl.
  • Mash with fork until blended and coarse crumbs form.
  • Set aside.
  • Spray 9-inch-diameter cake pan with 1 1/2-inch-high sides with vegetable oil spray.
  • Sift flour, sugar, baking powder, baking soda and salt into large bowl.
  • Whisk applesauce, buttermilk, oil, egg yolk, vanilla and lemon peel in medium bowl until well blended.
  • Add to dry ingredients and stir just until moistened (batter will be thick).
  • Beat egg whites in another large bowl until stiff peaks form.
  • Whisk half of whites into batter.
  • Fold in remaining whites.
  • Transfer batter to prepared pan.
  • Sprinkle topping over batter.
  • Bake cake until tester inserted into center comes out clean, about 30 minutes.
  • Transfer to rack; cool in pan.
  • Cut into 10 wedges and serve.