Preheat the oven to 350°F (175°C). Line the cupcake pan with cupcake liners.

In a mixing bowl, cream together the softened butter and granulated sugar using an electric mixer until light and fluffy.

Add the eggs, one at a time, mixing well after each addition. Then, mix in the lemon zest and lemon juice.

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

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

Divide the batter evenly among the cupcake liners, filling each about ⅔ full.

Bake for 15-18 minutes or until a toothpick inserted into the center comes out clean. Let the cupcakes cool in the pan for 5 minutes before transferring to a cooling rack to cool completely.

While the cupcakes cool, prepare the raspberry buttercream frosting. In a mixing bowl, beat the softened butter until creamy.

Gradually add the powdered sugar and mix on low speed until combined. Increase the speed and mix until fluffy.

Mix in the raspberry puree, vanilla extract, and salt. Adjust the consistency if needed with more powdered sugar or raspberry puree.

Once the cupcakes are completely cool, frost them using a piping bag or a spatula with the raspberry buttercream.