Preheat oven to 350°.
In a large bowl, mix all ingredients (it will bubble due to the reaction with the vinegar).
Grease your pan, then pour in your cake batter and smooth it out.
If adding topping, ensure to get a nice even layer across the top; too much in the corners will cause the sugar to burn.
For topping, use equal parts brown sugar and your nut of choice, crushed up and spread on top.
Bake for 35-45 minutes.
