Start by preheating your oven to 350°F. This ensures that the oven is at the right temperature when you’re ready to bake, which is crucial for even baking.

Grease and flour a 9×13 inch baking dish. This prevents the cake from sticking to the pan and makes it easier to remove after baking.

In a large bowl, mix water, mayonnaise, and vanilla extract. These ingredients form the wet base of the cake, and mixing them first ensures they are evenly distributed throughout the batter.

Add flour, sugar, cocoa, and baking soda to the bowl. These dry ingredients give the cake its structure and flavor.

With a hand mixer, blend the ingredients until you have a rich, moist cake batter. Be careful not to overmix as this can lead to a dense and chewy cake.

Pour the batter into the prepared baking dish. Make sure to spread it evenly for consistent baking.

Bake in the preheated oven for about 30 minutes or until a toothpick inserted in the center comes out clean. This ensures that your cake is perfectly baked, not underdone or overbaked.

Allow the cake to cool completely. This is important because it makes the cake easier to cut and it prevents the frosting from melting if you choose to frost it.