Preheat the oven to 350°F (175°C) and line a muffin tin with cupcake liners.

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

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

Stir in the lemon zest and lemon juice.

In another bowl, whisk together the flour, baking powder, and salt.

Gradually add the dry ingredients to the wet mixture, alternating with the milk, and mix until just combined.

Gently fold in the blueberries.

Divide the batter evenly among the cupcake liners and bake for 18-20 minutes or until a toothpick comes out clean.

Allow the cupcakes to cool completely before frosting.

In a mixing bowl, beat the softened butter until creamy.

Gradually add the powdered sugar, mixing on low speed until combined.

Add the lemon juice and lemon zest, then beat on high speed until fluffy.

If the frosting is too thick, add milk one tablespoon at a time until desired consistency is reached.

Once the cupcakes are cooled, frost them with the lemon frosting using a spatula or piping bag.

Optional: Garnish with additional blueberries or lemon zest on top.