First sift the flour and baking powder into a bowl. Then add the remaining ingredients except for the apples and biscuits and stir everything well. I use the blender to do this, but a large spoon will do the same.
Peel the apples and cut into small pieces. Crumble the speculoos in a freezer bag. Then briefly fold everything under the dough.
Line the muffin tin with molds and fill in the batter. I always take 2 tablespoons with it, it works quite well.
Bake the muffins in a preheated oven at 180 degrees top / bottom heat for 20-25 minutes.