Preheat oven to 180°C and line 3 x baking trays with baking paper.

Cream butter and sugar with an electric mixer until light and fluffy. Add egg and vanilla and beat until combined. Add baking powder and flour and use a wooden spoon to beat until combined. Work mixture into a ball, cover with plastic wrap and refrigerate for at least 1 hour.

Remove dough from the refrigerator. Break a section of dough and place it between two sheets of baking paper. Roll dough out until it's 5mm thick. Use a circular cookie cutter to cut into shapes. Place on prepared baking trays about 3cm apart. Repeat with remaining dough and any dough scraps until all the dough is shaped.

Bake in preheated oven for 8-10 minutes, or until cookies are golden. Remove from oven and leave on trays to cool completely.

When cookies have cooled, roll out fondant until a few millimeters thick. Use a cookie cutter the size down from the cookies to cut into shape. If using a stamp, press into fondant, then gently lift and place in the centre of cookies. Repeat until all of the cookies have been topped. Decorate with gluten-free sprinkles, if desired.