Toast the rice flour in a dry frying pan until warm and browned. Tip into the bowl of a food processor with the peanut butter and blend for up to 5 mins until smooth and beginning to clump together. Scrape down the sides with a spatula as needed. Taste and add sugar according toy our preference, and blend again until the mixture clumps together once more.

Press the mixture in an even layer in the base of a 20cm square dish lined with baking parchment, then cut into 16 squares. Will keep in an airtight container for up to a month.