Mix the sugar, butter, vanilla, and egg in a bowl.
Mix the flour, baking powder, baking soda, and salt together and add them to the butter bowl little by little. Add flour if necessary for a dough that does not stick to your hands.
Roll out the dough with a rolling pin on a floured surface and cut with cookie cutters.
Place them on a tray lined with baking paper and decorate with sprinkles.
Bake in the oven for 6–8 minutes, and serve after the cookies cool down.