Preheat your oven to 350°F (175°C).

In a large bowl, beat together the softened butter and granulated sugar until light and fluffy. Add the eggs, one at a time, mixing well after each addition. Then stir in the vanilla extract.

In another bowl, whisk together the flour, baking powder, baking soda, and salt. Slowly add this mixture to the butter-sugar mix, alternating with the buttermilk. Add a dash of red food coloring.

In a saucepan over medium heat, combine raspberries, sugar, and lemon juice. Cook until the raspberries break down and thicken.

Line a cupcake pan with liners and fill each about 2/3 full with batter. Drop a spoonful of the raspberry mixture on top of the batter and gently swirl it in.

Bake for about 18-20 minutes, or until a toothpick comes out clean. Let them cool completely before transferring to a wire rack.

In a mixing bowl, beat together the softened butter and powdered sugar. Gradually add heavy cream, vanilla extract, and a pinch of salt.

Using a piping bag or spatula, frost your cooled cupcakes. Optionally, top with fresh raspberries.