Preheat your oven to 350°F (175°C) and line a cupcake pan with paper liners.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
In a large bowl, cream the softened butter and granulated sugar together until light and fluffy. This should take about 3-4 minutes.
Add the eggs one at a time, mixing well after each addition. Then stir in the lemon zest and lemon juice.
Gradually add the dry ingredients to the wet mixture, alternating with the buttermilk. Start and end with the dry ingredients. Mix until just combined.
Gently fold in the diced strawberries, being careful not to overmix.
Divide the batter evenly among the cupcake liners, filling each about two-thirds full.
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.
Allow the cupcakes to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.
To prepare the frosting, in a medium bowl, whisk together the powdered sugar, lemon juice, and milk until smooth and creamy. Adjust the consistency as necessary with more powdered sugar or a little more milk.
Once the cupcakes are completely cool, frost each with the lemon frosting using a piping bag or a knife.
Top each cupcake with a fresh strawberry for garnish.
Notes
For best results, use fresh strawberries and allow cupcakes to cool completely before frosting.