Line a baking tin (18 cm x 12 cm) with non-stick baking paper – extend paper above the sides, so you can pull a slice out when it is set.
To make the base, process all ingredients in a food processor until crumbly and mixture starts to stick together – don’t over-process as you want a little texture.
Spread the mixture into the prepared slice tin and press down firmly to form the base. Refrigerate while you make your blueberry filling.
To make the blueberry filling, blend drained cashews, blueberries, maqui powder, coconut oil, agave, lemon juice in a high-speed blender. Blend on high speed until mixture becomes creamy and smooth.
Pour the blueberry filling over your base and put it in the fridge to firm up while you make your chocolate topping.
Return to freezer for 4-5 hours (or refrigerate overnight) until set.
You can store it in fridge or freezer. Remove it from freezer 10 minutes before eating, to soften slightly.
You can decorate it with chocolate, dried raspberries or some flowers.