So first set the oven to 180'C/Gas 4. Line a small baking tin (approx 20cm) with baking paper.
Put 200g butter, 200g light soft brown sugar and 5 tbsp maple syrup into a large microwaveable bowl. Put on a low setting for approx 2 minutes until melted, checking on it and stirring after a minute (if you'd prefer, you can do this in a saucepan on the hob).
You should get a sticky and oozy brown toffee-like sauce.
Stir in 50g sesame seeds and 250g oats.
Spoon the mixture into the baking tin.
Sprinkle with the an extra 1 tbsp of sesame seeds, and bake in the oven for 20-25 minutes, until golden brown and slightly dark around the edges.
Leave to cool for 10 mins, mark into approximately 12 squares, then leave to harden.
Lift the paper and flapjack out of the tin, then cut into squares. Enjoy with a cup of tea!