- Preheat oven to 350°F.
- Combine flour, corn starch, baking soda, baking powder, and salt in a small bowl; set aside.
- Whisk sugar, buttermilk, eggs, egg whites, corn syrup, butter, oil, vanilla, and almond extract, if desired, in a large bowl. Gradually stir in flour mixture until smooth. Pour batter into a greased 13 x 9-inch baking pan.
- Bake 25 to 29 minutes until a toothpick inserted in center comes out clean. Cool in pan on wire rack.
- Frost cooled cake with Fluffy Cocoa Frosting or Fluffy Frosting.
NOTE: To make Buttermilk Birthday Cupcakes, follow the recipe as directed, after mixing batter, divide batter evenly into 24 greased or paper-lined (2-1/2 inch) muffin cups. Bake 18 to 22 minutes, or until the toothpick inserted in the cupcake comes out clean.
*TIP: To make sour milk, combine 1-1/4 teaspoons lemon juice (or vinegar) with enough low-fat milk to measure 1-1/3 cups. Let stand 5 minutes.