In a medium saucepan over medium-high heat, combine the ingredients for the raspberry filling. Stir to combine and simmer for 10 minutes, stirring occasionally to break up the berries. Once thickened, remove from heat. Cool completely in the refrigerator or freezer (be careful not to let it freeze!).

Preheat oven to 350 degrees. Line two 12-cup cupcake tins with cupcake liners or grease well.

In a large bowl, sift the flour, baking powder, baking soda, and salt together. Set aside.

In the bowl of an electric stand mixer, using the paddle attachment, beat butter on medium speed with the sugar until it forms a softened paste, approximately 1 minute. Add the eggs in one at a time, beating after each until incorporated, making sure to scrape down the edges as needed.

Set the mixer to a low speed and alternate between adding the flour mixture and the buttermilk, working in two batches for each. Once fully incorporated, beat in the vanilla, lemon juice and lemon zest.

Divide the batter evenly between the cupcake pans, filling each cupcake liner approximately three-quarters full. Bake in the oven for 20 to 25 minutes or until a cake tester comes out clean. Transfer the pans to wire racks and cool for at least 15 to 20 minutes, before turning out the cupcakes to cool completely.

While the cupcakes are cooling, make the frosting. In a clean bowl using a hand mixer or in the bowl of a stand mixer, beat butter for approximately 1 to 2 minutes. Beat in sugar slowly on low. Add white chocolate, salt, milk and vanilla extract and beat on low until incorporated. Increase speed to medium and beat until smooth and fluffy, approximately 4 to 5 minutes. If the icing is too thick, add more milk (1 Tbsp at a time) until desired consistency is reached.

Using a cupcake corer (or a small pairing knife), remove the center of each cupcake. The hole you create should be about a 1/2 inch to 3/4 inch deep. Fill each cupcake with approximately 1 to 2 tsp of the raspberry filling.

Frost cupcakes as desired and garnish with raspberry on top.