01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl. Set aside.
03 - Beat butter and sugar in a large bowl until light and fluffy, about 2-3 minutes.
04 - Add eggs one at a time, beating well after each addition. Mix in lemon zest, lemon juice, and vanilla extract.
05 - Add dry ingredients in three parts, alternating with milk, beginning and ending with flour. Mix until just combined; do not overmix.
06 - Divide batter evenly among cupcake liners, filling each about 2/3 full.
07 - Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Let cool in pan for 5 minutes, then transfer to wire rack to cool completely.
08 - Beat butter in a medium bowl until creamy. Add powdered sugar gradually, beating until smooth.
09 - Mix in strawberry puree, vanilla extract, and pinch of salt. Beat until fluffy and pink. Adjust consistency with extra powdered sugar or puree as needed.
10 - Once cupcakes are completely cool, pipe or spread strawberry buttercream on top.