Preheat the oven to 180 degrees Celsius or 356 degrees Fahrenheit. Line a large rectangular baking tray with baking paper.
To brown the butter, place it in a small saucepan over a low heat and allow to cook until nutty in fragrance and dark brown in colour.
Whisk together all the ingredients until smooth and set aside to thicken for 5 minutes.
Once thickened slightly (the consistency of a thick crepe batter) pour onto the lined baking tray. Use an offset spatula or a flat knife to spread the batter across the baking paper. How thin you want to go is up to you – I normally just spread it enough to cover the majority of the sheet.
Place the baking tray in the oven. If you’d like to score the crackers, set the timer for 5 minutes before using a pizza cutter to slice. They’ll contract and split from each other so you don’t need to worry about getting right to the edges. If you’d prefer to snap them (makes for more rustic crackers) just leave them in the oven for 20-30 minutes or until completely cooked through and lightly browned.
Store in an airtight container.