Raspberry Buttercream Filling
- 1/4 cup salted butter
- 3/4 cup confectioners sugar
- 1 cup fresh raspberries
- To make the buttercream, whip the butter with an electric mixer until pale and fluffy.
- Slowly add sugar.
- Add the raspberries to a saucepan with a splash of water and cook over low heat for about 10 minutes until raspberries are cooked down.
- Work the raspberries through a sieve held over a separate bowl to extract the seeds. You want to extract about 3 tbsp of juice. Use more raspberries if necessary.
- Add the juice to the butter cream, then whip until combined.
- Add the cream to a pastry bag fitted with a small tip. Reverse the cookie shells onto their backs.
- Pipe a small mound of filling in the center of one of them, then top with another shell.
- Serve immediately, or store in fridge until serving time.