Preheat the oven to 190C/170C Fan/Gas 5. Grease a 20cm/8in square baking tin and line it with baking paper, or use a silicone liner.

Put the butter and syrup in a large microwave-safe bowl and microwave for 40 seconds. Stir, and if the butter hasn’t melted, return to the microwave until melted.

Add the oats, sultanas and bananas and mix well.

Press into the baking tin, cover with foil and bake for 30 minutes, removing the foil for the last 10 minutes.

Mark the flapjack into 12 pieces without cutting all the way through; this will make it easier to cut the flapjack when it’s cool. Leave until cold and then cut into pieces.

Store in a tin or airtight container for up to 3 days.