Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
In a mixing bowl, cream together the butter and sugar until light and fluffy.
Add the eggs one at a time, beating well after each addition.
Mix in the vanilla extract and lemon zest.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, alternating with the milk, beginning and ending with the dry ingredients.
Gently fold in the blueberries.
Divide the batter evenly among the cupcake liners, filling each about ⅔ full.
Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cupcakes to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.