Preheat the oven to 180c/350f.
Add all of the ingredients to a bowl and stir to combine.
Add the mix to a lined baking dish (ours is 20x20cm), smooth the top with the back of a spoon then bake for 25-30 minutes until golden around the edges.
Allow to cool in the dish (this firms up as it cools).
Slice into 20 pieces and enjoy hot or cold.
Store in the fridge for 3 days or freezer for 2 months.