Mix the self-rising flour, sugar, speculaas spice mix and salt. Add the butter and milk and knead into a firm ball of dough. Start with 6 tablespoons of milk, if the dough is too stiff you can add more milk.

Wrap the dough in plastic wrap and refrigerate overnight. You can process and bake it immediately, but the flavor will be much better if you let it rest.

Mix the almond paste with half of the beaten egg and knead well. This makes it easier to work with and gives it a better and tastier texture.

Take half of the dough and roll it out to 20 x 20 cm. Place in a baking pan lined with parchment paper. Spread the almond paste mixture evenly. Roll out the remaining dough and place on top of the almond paste.

Brush the top with the remaining beaten egg. Garnish with almonds and top with another layer of egg wash.

Bake the filled speculaas for 40 minutes at 180°C/350℉ (conventional oven) or until done.