Preheat the oven to 180°C (160° fan/ 350F/ Gas Mark 4) and grease and line a 20cm (8") square baking tin with baking paper.
Place the oats, flour, light brown sugar, and desiccated coconut into a large mixing bowl.
100 g Oats, 130 g Plain Flour, 120 g Light Brown Sugar, 60 g Desiccated Coconut
In a saucepan, melt the butter, syrup, and 1 tablespoon of water together on a medium heat.
125 g Butter, 2½ tablespoon Golden Syrup, 1 tablespoon Water
Take the saucepan off the heat and stir in the bicarbonate of soda (it will froth).
½ teaspoon Bicarbonate of Soda
Pour the melted butter and syrup mixture into the flour and oat mixture and stir to combine.
Press into the prepared tin and bake in the oven for 20-23 minutes. Cool completely before cutting into 8 large rectangular bars of 16 smaller square bars.