Line a 20 cm/7-inch square baking tin with greaseproof paper/ parchment paper.
Place the butter, honey and vanilla extract (if you use flavouring) in a pan. Cook it until butter and honey melt, and the mixture bubbles on the edges and is slightly foamy in the middle.
Add the oatmeal porridge to the butter mixture and continue cooking for 2-3 minutes until the liquid evaporates.
Add the chopped dates and stir well.
Put the flapjack mixture onto the lined baking tin. It will be thick and sticky. You can use a spatula or a spoon to spread evenly and press it lightly.
Sprinkle the sesame seeds over the flapjack and press it lightly with the spatula or the back of a spoon.
Leave it cool and set.
Notes
I strongly recommend you use set honey. But of course, you can use runny honey. Though it may take longer to cook the oatmeal until the liquid is absorbed by the oatmeal.
You can swap the dates with other dried fruits that you like. Raisins, sultanas, apricots, and figs are all good choices.
If you want to put seeds such as pumpkin seeds or sunflower seeds in the mixture, try to roast them in a pan and cool them before using. So they will be crunchy. And you can stir them into the mixture just before all the liquid disappear.
Nutritional info in this recipe is only estimate using online calculator. You should refer to it as a guide only. Please verify with your own data if you seek an accurate info.