Preheat oven to 350°F (175°C) and line a 12-count muffin tin with paper liners.

In a medium bowl, whisk together flour, baking powder, baking soda, and salt until homogenous.

Using a stand mixer with a paddle attachment, cream 0.5 cup butter and granulated sugar on medium-high speed until light and aerated, approximately 3 minutes.

Incorporate eggs one at a time, followed by lemon zest and 1 teaspoon vanilla extract, beating well after each addition.

In a separate vessel, whisk together the milk, lemon juice, and sour cream.

Reduce mixer speed to low and add the dry ingredients in three parts, alternating with the liquid mixture, beginning and ending with the dry ingredients.

Distribute the batter evenly into the cupcake liners, filling each approximately 2/3 full.

Bake for 18 to 20 minutes or until the internal temperature reaches 205°F (96°C) or a tester comes out clean.

Transfer to a wire rack and allow to cool completely to room temperature.

For the frosting, beat 1 cup softened butter until smooth. Gradually incorporate powdered sugar on low speed.

Add the strained raspberry puree, 0.5 teaspoon vanilla, and a pinch of salt. Increase speed to high and whip for 2 to 3 minutes until light and fluffy.

Pipe the raspberry buttercream onto the cooled cupcakes using a star tip.