Preheat oven to 350°F and spray an 11x7 baking dish with nonstick cooking spray.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, and salt.
Make a depression in the dry ingredient mixture. Pour in the water, oil, vinegar, and vanilla extract into the bowl with the dry ingredients. Whisk to combine.
Pour the cake batter into the prepared baking dish and bake for 30-35 minutes. The cake is full baked when a toothpick inserted in the center of the cake comes out clean.
Allow the cake to cool completely and then frost with chocolate frosting (or your favorite frosting!)
Notes
You can make this recipe gluten-free by using gluten-free flour. Substitute for regular flour and follow the recipe.Please note that all nutritional values are estimates. Exact values depend on the ingredients used to make the recipe.