Preheat the oven to 352 F (160 C).
Line a 12-cup muffin tin with paper liners.

In the bowl of a mixer, cream the butter with the sugar, then add the eggs one at a time, beating well after each addition.
Beat until light and fluffy.

Add the milk, flour, baking powder, salt, and vanilla seeds, and mix well, then stir in the raspberry puree.

Divide the mixture evenly among the muffin cups.
Bake for 25 minutes or until the cupcakes are firm to the touch.
Let cool for a few minutes before transferring to a wire rack.
Let cool completely before frosting.

Finish:
In a small bowl, beat the powdered sugar and butter with an electric mixer until light and fluffy.

Put the mixture in a piping bag fitted with a star tip and decorate the cupcakes.
Top with a raspberry and serve.