1) In a bowl cream together butter and sugar till light.
2) Add an egg and jam and whisk again.
3) Sift the flour and mix it with the baking powder and gradually add this mixture to the bowl.
4) Roughly chop up the white chocolate and add it to the dough.
5) Freeze the dough for around 15 minutes.
6) Make small balls and place them on a cookie tray and bake at 180 degrees for 12 minutes.
7)They should be baked just enough so that they have a crispy shell with a gooey centre.
8) You can also freeze the cookie dough for about a month and use it anytime.