Add in the vinegar, vanilla, oil, and water, and stir until well combined. Pour the cake batter into the baking dish.
1 teaspoon vinegar, 2 teaspoons vanilla extract, 1/3 cup vegetable oil, 1 cup water
Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean. Eat the chocolate cake warm or cool completely and frost, if desired.
Notes
To make it gluten-free, swap in a cup-for-cup gluten-free all-purpose flour.Store leftovers in an airtight container in the fridge for up to 1 week, or freeze frosted or unfrosted slices for up to 3 months.Most frostings contain butter or milk, so dust the top with powdered sugar if you need the cake to stay dairy-free.