1. Preheat oven to 180C/350F. Line a 9×9 square tin (or equivalent) with parchment paper and set aside.
2. Combine the almond flour, coconut flour, salt, shortening and maple syrup in a food processor and process until the dough is uniform and comes together.
3. Press to the bottom of the baking tin and bake in the oven for 12-15 minutes, until browned. Cool completely.
4. Make the caramel by whisking together the almond butter, tahini, maple syrup, vanilla, coconut oil and salt.
5. Pour on top of the shortbread and set in the fridge for at least 2 hours.
6. Melt the chocolate in a bowl over a water bath and pour on top of the caramel.
7. Place in the fridge until set, then cut into bars. Best kept in the fridge.
