In a large mixing bowl, mix together the sugar, salt, baking powder and flour.

Rub the butter into the dry ingredients with your fingertips until the mixture resembles wet sand or breadcrumbs. I prefer to do this in my KitchenAid stand-mixer with the flat paddle attachment.

Add the 2 eggs and mix until you have a soft dough.

Shape the dough into a long sausage, about 3 cm (roughly 1 inch) in diameter.

Cover the dough with cling film, and leave it to chill in the fridge for about 30 minutes.

Preheat the oven to 160°C (320°F) (without fan).

Remove the cling film, and slice small rounds from the dough, about 2 cm thick. You could use the rounds as they are or, alternatively, roll them into balls to create more rounded cookies.

Place the rounds on a baking sheet lined with baking paper.

Flatten each round slightly.

Press a whole almond in the centre of each round.

Lightly whisk the remaining egg yolk in a small bowl, and brush the top of each cookie with this egg-wash.

Bake the cookies for about 20 minutes, or until they are lightly golden.

Allow the cookies to cool on the tray for about 5 minutes before removing.