Preheat the oven to 150°C (300°F). Lightly grease and line a large baking tray with plastic-free baking parchment.
Place all the ingredients in a large bowl and mix until well combined. Set aside for 5 minutes.
Spoon the mixture onto the prepared tray and spread evenly using the back of a spoon. Refrigerate for 10 minutes to firm up, then bake for 20 minutes. Remove from the oven and cut into rectangles. Turn the crackers over and bake for another 15 minutes, or until crisp.
Notes
Crackers will keep in an airtight container for up to three days.