Combine the purée and maltodextrin well. Spread evenly over a non-stick baking mat to 3 mm (⅛ inch) thick and place on a baking tray. Dry in a dehydrator at 80°C (176°F) for 1 hour. Alternatively, place in the oven on the lowest temperature and leave until completely dry. Remove and allow to cool. Scrape into a food processor, add the ground almonds and pulse until fine crumbs form. Transfer to a bowl and stir in the sesame seeds. Set aside.
This can be made up to 1 day in advance and stored in an airtight container in the fridge.