01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners.
02 - In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
03 - In a large bowl, beat the butter and sugar together until light and fluffy.
04 - Add eggs one at a time, beating well after each addition. Mix in lemon zest, lemon juice, and vanilla extract.
05 - Add half of the flour mixture to the wet ingredients, mix gently. Pour in the milk, mix, then fold in the remaining flour mixture until just combined.
06 - Toss blueberries with 1 tablespoon flour, then gently fold into the batter.
07 - Divide batter evenly among muffin cups, filling about 3/4 full.
08 - Bake for 18–20 minutes, or until a toothpick inserted in the center comes out clean. Let cool completely before frosting.
09 - Beat butter and cream cheese together until smooth. Add powdered sugar, lemon juice, and lemon zest; beat until light and fluffy.
10 - Frost cooled cupcakes and garnish with extra blueberries or lemon zest if desired.