Beat the butter and sugar together until pale, then mix in the egg.

Sift the flour and baking powder into the mixture and bring together into a soft dough.

Roll the dough into walnut-sized balls, arrange on a tray, and press a small hollow into the centre of each with your finger.

Fill each hollow with a teaspoon of strawberry jam and bake in an oven preheated to 175°C for 20 minutes until the edges turn lightly golden.