Lightly oil a 9x13-inch pan and set aside. In a large bowl, sift together the flour, sugar, baking soda, and salt. In another bowl, place the water, lemon juice, oil, vanilla, and lemon oil (if using), and whisk well to combine. Add the wet ingredients to the dry ingredients and whisk well to combine. Drizzle the vinegar over the top of the batter and whisk quickly to thoroughly incorporate. Pour batter into the prepared pan. Bake at 350 degrees for 20-25 minutes or until an inserted toothpick comes out clean. Serve plain or frost with Fluffy Lemon Frosting or Vanilla "Buttercream" Frosting or other frosting of choice.

Yield: One 9x13-inch cake