Mix the oat flour, cocoa and a pinch of salt in a bowl. Pour in the tahini, maple syrup and coconut oil. Mix until you have a well combined dough. Press into square silicon moulds, brownie moulds or a 8" square cake tin lined with baking paper. Freeze for 30-60 minutes, then remove from the moulds or slice into 12 squares if using a cake tin.
You have the option to dip them in melted chocolate for extra decadence and drizzle a little more chocolate on top. Or you can coat them in chocolate. Store in an air-tight container in the fridge for up to 5 days.