1 1/2 cups butter
1/2 cup white sugar
2/3 cup packed light brown sugar
2 tablespoons white vinegar
1 teaspoon vanilla extract
2 1/2 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon salt
1 tablespoon lemon juice
Preheat oven to 375 degrees F (190 degrees C). Grease and flour two 9-inch round baking pans.
Sift together the butter, brown sugar, white vinegar, light brown sugar, white vinegar, flour, baking soda and salt. Fold the flour into the mixture until just moist. Stir together the lemon juice and lemon zest. Bake in preheated oven for 20 minutes, or until a toothpick inserted in the center of the cake comes out clean. Cool completely.