Preheat oven to 350°.
Line an 8-inch square baking pan with aluminum foil. Coat foil with cooking spray; set aside.
Lightly spoon flour into a dry measuring cup; level with a knife.
Combine flour, sugar, cocoa, and soda in a medium bowl. Combine applesauce and next 4 ingredients, and stir with a whisk; gradually add to dry ingredients, stirring just until blended. Pour batter into prepared pan. Bake at 350° for 18 minutes. (Wooden pick will not come out clean.)
Cool in pan on a wire rack. Cut into 16 squares; cut each square in half diagonally, creating triangles. Arrange 2 triangles on each serving plate. Spoon 1/4 cup ice cream on top of each serving. Drizzle each serving with 1 tablespoon chocolate syrup. Serve immediately.