Preheat your oven to 350°F. Grease and flour your cake pan(s) (or line the bottom and sides with parchment paper).
Place all of the ingredients in a medium to large mixing bowl. Mix until the batter is smooth and homogenous with no dry ingredients remaining.
517 g DIY Vanilla Cake Mix, 3 eggs, 100 ml oil, 150 ml water
Pour the batter into the prepared pan(s) (if using 2-8x8 inch pans, ensure the batter is evenly divided between the two). Tap the pans lightly on the counter to release any large bubbles.
Bake in your preheated oven for 25-28 minutes or until a toothpick inserted halfway between the center and the edge of the pan comes out with a few moist crumbs.
Cool in the pan(s) for about 5 minutes before turning out onto a wire rack. Cool completely before frosting.