In a bowl place the butter and sugar, mix until both ingredients are integrated.
Add the egg yolk and a whole egg, beat for a couple of minutes, then add the cornstarch and flour, mix well. Refrigerate for 10 minutes.
On a table sprinkle a little flour and stretch the dough until it is smooth, with a hope of 0.5 cm approximately.
Toma un molde redondo pequeño para cortar la masa, Colocar nuestro alfajores en una bandeja panadera. Llevar al horno por 15 minutos. Dejar enfriar
Add the dulce de leche to the alfajores and gather in pairs. Sprinkle with icing sugar or immerse the alfajores in melted chocolate, then take them to the fridge for 1 hour and then consume.