Mix the butter and caster sugar and salt. Add buttermilk and stir until the dough is smooth. Knead with the flour, baking powder and speculaas spices.

Ideal: let the dough rest for 2 days in the refrigerator to give the flavours change to blend together well.

Roll the dough on a slightly floured working surface. Roll out to a slice of 3 mm. Cut rectangles of 4 x 5 cm and bake 30 minutes in an oven of 150ºC.