Argentine cornflour alfajores with dulce de leche

1. Beat the soft butter and sugar until fluffy, then add the egg yolks one at a time and the grated lemon zest.

2. Sift together the cornflour, flour and baking powder and add to the butter mixture; knead only until it comes together – overworking makes it tough.

3. Wrap the dough in cling film and chill for 30 minutes.

4. Roll out 5 mm thick on a floured surface, cut out discs with a 5 cm round cutter and bake on a lined tray at 170 °C for 10-12 minutes – the discs should stay pale with only the bottoms colouring; cool completely (they're very fragile).

5. Spread a thick layer of dulce de leche on the underside of half the discs and top with the remaining discs.

6. Roll the creamy edges in desiccated coconut.

Tip: Alfajores de maicena are the softest, most crumbly kind of alfajor – after a day's rest the biscuits absorb moisture from the filling and practically melt in your mouth.