Preheat the oven to 150°C and line a 20cm/8inch square baking tin with parchment paper.
Melt the butter in a medium pan over a low heat and line the baking tine with a bit of butter.
Add the honey and sugar to the butter and heat gently. Once the sugar is dissolved and the butter is melted, remove the pan from the heat and stir in the porridge oats.
Pack the mixture into the baking tin and squash down. Bake in the oven for 40 minutes.
Once cooked, remove from the oven, leave to cool for 15 minutes, then turn out onto a chopping board and cut into squares.