Preheat the oven to 350°F (175°C).

In a mixing bowl, cream together the butter and sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition.

Stir in the vanilla extract and lemon zest.

In another bowl, combine the flour and baking powder.

Gradually add the dry ingredients to the wet ingredients, alternating with the milk, and mix until smooth.

Pour the batter into cupcake liners or molds, filling each about 2/3 full.

Bake for 30 minutes or until the tops are golden and a toothpick inserted comes out clean.

Allow the cupcakes to cool before serving.