Add the sugar, ground almonds and egg white to a bowl and mix with a rubber spatula or wooden spoon. Add the flour and almond extract and stir to combine.
Transfer your mixture to a piping bag and snip the end or use a wide piping tip to pipe 2 inch circles of cookie dough onto your baking sheet. Just holding the piping back straight up and down over the baking sheet and squeeze to let the circle fan out.
Optional: press a slivered almond or a candied almond into the center of each cookie.
Bake for about 20 minutes until golden and crackly.