Preheat the oven to 180c/350f.
Add all the slice mix to a food processor and blend until combined and no large chunks of nuts/apple remain. If mixing by hand finely chop the nuts and cook & mash the apple.
Spread the mix into a lined dish (we use a 7”x4” dish but any works - may need extra raspberries if using a larger dish & less baking time if the slice base is thinner). Reserve 2 Tbsp to use as the “crumble.”
Add the raspberries & spread evenly with a spoon to create a jam like layer. Then add the crumble by placing little bits scattered on top and gently mixing in with a spoon/fingers to add some clusters.
Bake in the oven for 35-40 minutes until cooked. Allow to cool in the dish (this will firm up as it cools).
Once firm, slice into ~ 12 slices and serve warm or cold.
Store in the fridge for 3 days or freezer for 3 months.
