Preheat oven to 350 °F. Mix dry ingredients. Add wet ingredients and mix thoroughly. Spoon into prepared muffin tins.
Bake 25 - 30 minutes.
Notes
Recipe may be doubled to make a 9x13 or two-level round cake. Baking time will increase; monitor.
Substitutions
For vinegar: apple cider vinegar works well.
You can omit cocoa and increase vanilla for vanilla cupcakes.
Gluten: Gluten is a protein found in specific grains (wheat, spelt, kamut, barley, rye). Other grains are naturally gluten-free but may have cross-contact with gluten-containing grains. Look for certified gluten-free products if you need to avoid gluten. Find out more about wheat and gluten substitutions.