1 cup buttermilk or sour milk
3/4 cup granulated sugar
1/2 cup vegetable oil
1 tsp vanilla
1 tsp grated lemon zest
2 cups all-purpose flour
2 tsp baking powder
1/2 tsp baking soda
Preheat oven to 375 F. Grease or line a 12-cup muffin pan.
In large bowl, beat together the sugar, oil, eggs, vanilla and lemon zest until light(ish).
In another bowl, mix together the flour, baking powder and baking soda. Stir this mixture into the egg mixture, in 2 or 3 additions, alternately with buttermilk. Beat only until combined - don't overbeat! - then spoon the batter into the well-greased (or paper-lined) muffin pan, filling the cups nearly to the top. Bake for 20 to 25 minutes, until lightly browned on top. Makes 12 muffins.
Blueberry Muffins: Stir 1 cup fresh or frozen (don't defrost them) blueberries into the batter before spooning it into the muffin pan. Bake as for buttermilk muffins.
Chocolate Chip Muffins: Stir 1 cup chocolate chips into the batter before spooning it into the muffins pan. Bake as for buttermilk muffins.
Poppy Seed Muffins: Mix 1/4 cup poppy seeds into the buttermilk and let soak while you prepare the rest of the ingredients. Add to the batter and bake as for buttermilk muffins.
Cranberry or Cherry Muffins: Stir 1 cup of chopped dried cranberries or dried cherries into the batter before baking. Bake as for buttermilk muffins.
Source: The Clueless Baker, 2001