Pre-heat the oven to 180 degrees C
Line a baking tray or grease
Melt the butter gently in a saucepan
Remove from heat
Mix in the sugar
Mix in the oats
Press the mixture evenly into the tin
Bake in the oven for 15 minutes or until golden brown
Remove from the oven and score into 12 pieces
Leave to cool
Remove from tin and consume or store in an air tight container