1/2 cup milk
1 teaspoon vanilla extract
1 cup packed light brown sugar
1 egg
2 1/2 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon baking powder
1 teaspoon baking soda powder
1/4 teaspoon salt
1 tablespoon ground cinnamon
Place milk, vanilla, brown sugar, egg, flour and baking soda in small mixing bowl.
Lightly grease a 9x13-inch pan with nonstick spray.
Dissolve brown sugar in flour, leaving 1/2 cup. Mix together 1/2 cup of flour with baking soda. Coat 1/2 cup of crumbs over bottom of prepared pan.
Stir remaining 1/2 cup of flour into crumb mixture. Place over sugar rim of pan.
Beat egg whites into crumb mixture. Stir in 1/2 teaspoon salt, if desired. Spread over crumb mixture. Sprinkle with remaining cinnamon.
Bake in preheated oven for 1 hour or until set. Cool completely.