In a food processor, combine self-rising flour, speculaas spice mix, dark brown sugar, baking powder, and salt. Pulse until well mixed. Add cold, cubed butter and pulse until resembling coarse meal.

Mix in the egg yolk, slivered almonds, and milk into dough until it forms a cohesive ball. Wrap in plastic wrap and refrigerate for at least 1 hour.

Preheat your oven to 350°F (180°C) and grease a mini muffin tin.

Dust surface with flour and roll out dough to about ⅕ inch thick. Use cookie cutter to cut dough into 2 or 4-inch circles. Press into muffin tin.

Fill each dough cup with a heaping spoonful of almond paste, cover with another dough circle, pressing edges to seal. Place a whole almond on top, and brush with beaten egg.

Bake for 15 minutes for mini cookies or 20 minutes for larger ones until golden brown. Allow to cool before transferring to a wire rack.

Once cooled, serve with a warm cup of coffee or tea and enjoy.