Crumble the spiced cookies in a ziplock bag by using a rolling pin or your hand to break them up into chunks without any mess. Alternatively, you can use a food processor and pulse them briefly. You don't want the crumbs to be too fine.
250 g spiced cookies
Combine the cookie crumbs with the melted butter in a small bowl.
6 tbsp butter
Peel, core, and dice the apples into 1/2-inch pieces.
4 apples
Layer the apple pieces in an 8x6 inch baking dish and sprinkle the biscuit topping evenly over them. Add the ground cinnamon if you're using it. Stir to combine.
Pour the water over the apples and add the cookie mixture on top (Note 1).
1/3 cup water
Cover it with baking paper or tinfoil and bake for 35 minutes or until the apples are soft. Remove the foil for the last 5 minutes of baking for the topping to crisp up (Note 2).
Let the apple crisp sit for at least 5 minutes before serving to set and to cool down slightly. Add some powdered sugar before serving (optional).
1 tsp powdered sugar
Notes
Note 1: The water helps soften the apples while cookies and ensures they remain juicy.Note 2: The apples should be tender but still hold their shape. Covering it with baking paper prevents it from burning as the cookies are already baked.Storage: Store leftover apple crisp in an airtight container or up to 4 days or freeze for up to 3 months. Simply reheat it in the oven or microwave for a quick dessert.