Pre-heat the oven to 180 °C/gas mark 4.
Line a square 8inch loose bottomed tin with baking parchment.
Melt the butter in a large pan along with the sugar and syrup, then stir in the oats.
Press down into the tin until the mixture is level.
Bake in a pre-heated oven for about 20 minutes or until golden brown.
Remove from the oven and leave to cool in the tin for about 10 minutes then move to a cooling rack.
Once cooled, cut it into either 8 rectangles or 16 snack sized squares.