01 - Preheat oven to 350°F. Line a 12-cup muffin tin with cupcake liners.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until evenly distributed.
03 - In a large bowl, beat the softened butter and granulated sugar together using an electric mixer until the mixture becomes pale, light, and fluffy.
04 - Add the eggs one at a time, beating well after each addition to ensure full incorporation before adding the next.
05 - Mix in the fresh lemon juice and finely grated lemon zest until evenly combined throughout the batter.
06 - Gradually add the dry ingredient mixture to the wet ingredients, alternating with the whole milk. Begin and end with the dry ingredients, mixing until just combined. Avoid overmixing.
07 - Gently fold the diced fresh strawberries into the batter using a spatula, taking care not to crush the pieces or deflate the mixture.
08 - Divide the batter evenly among the cupcake liners, filling each one approximately two-thirds full to allow room for rising.
09 - Bake for 16 to 18 minutes, or until a toothpick inserted into the center of a cupcake comes out clean. Rotate the pan halfway through for even baking.
10 - Remove the cupcakes from the muffin tin and transfer them to a wire rack. Allow them to cool completely before frosting.
11 - Beat the softened butter until creamy and smooth. Gradually add the sifted powdered sugar, beating continuously. Pour in the lemon juice, strawberry puree, vanilla extract, and a pinch of salt. Beat until the frosting is light, fluffy, and well combined.
12 - Once the cupcakes have cooled completely, frost each one generously with the strawberry lemonade buttercream. Garnish with thin strawberry slices or a sprinkle of lemon zest if desired.