To make the raspberry jam, combine all the ingredients in a saucepan over medium heat then allow to come to a boil and cook for 10 minutes. To test if the jam is ready, spoon some of the jam onto a plate, allow to cool slightly and drag your finger through the mixture. If the liquid doesn't bleed into the line again, the jam is ready.
Transfer the jam to a sterilized jar and allow to cool completely.
To make the cookies, pre-heat the oven to 180°c and line two baking trays with baking paper.
Beat the butter and sugar together in a bowl until light and creamy then beat in the egg. Sift together the flour and baking powder and fold into the butter mixture. Mix until the dough comes together in a ball then bring together with your hands, making sure the dough has been mixed through.
Form balls just smaller than the size of golf balls and place them on the baking trays. Flatten with a fork then place in the oven and allow to bake for 10-15 minutes or until the cookies are golden brown and cooked through.
Remove from the oven and allow to cool completely.
While the cookies cool, whip together the butter and sugar for the butter cream until light and fluffy. Add the cream and vanilla seeds and mix through.
Sandwich the cookies with a bit of the raspberry jam and the vanilla butter cream.
Place in the fridge to set for 10-20 minutes before serving.