Makes 48 small cupcakes. These are very moist and delicious but not terribly lemony. Very good with a topping of a layer of raspberry jam and lemon buttercream. The original recipe is from Taste of Home, but had a yield of only 30. By dividing up the batter to make 48 I've made the recipe yield smaller cupcakes that have room for the jam and a nice layer of buttercream.
In a mixing bowl, cream butter and sugar. Beat in eggs, one at a time. Add lemon oil or zest and vanilla; mix well. Combine dry ingredients; add to creamed mixture alternately with sour cream (batter will be thick). Fill foil-lined muffin cups enough batter to fill about 1/3 of the muffin tin. (Yes, only 1/3. You want these to be small. And foil cupcake liners work much better than paper ones, as they are easier to peel off. A quick spritz of baking spray makes them even easier.) Bake at 350 degrees F for 15 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes; remove to wire racks and cool completely.
*I keep lemon oil on hand and always use it in place of zest. It is pressed from lemon peel, so it is the substance that gives lemon zest its flavor and is extremely strong. Be very careful not to overdo this ingredient, as you can ruin a whole batch that way. If you taste the batter and feel that it's not lemony enough, add additional oil literally drop by drop. Citrus oils last forever in the fridge.