Preheat the oven to 180C (160 Fan) and line baking trays with parchment paper. I used two large baking trays but you need to ensure that the cookies are spaced out enough so that when they spread in the oven they don’t touch.
Mix together the sugar and butter until light and creamy and fluffy. Add in the flour, egg, vanilla and baking powder and mix until it forms a dough.
Split the dough into 12 equal balls and place on your baking trays.
Press your thumb into the centre of each dough ball to create a well.
Fill the well with jam and bake in the oven for 10-15 minutes or until they are golden brown.
Remove them from the oven and leave to cool on the baking tray for 15 minutes and then gently move them to a wire rack to cool fully.