Grease an 8 inch round baking tin with butter then line the base with baking parchment

Preheat the oven to 170°C/ 325°F/ GM 3

Put the butter, sugar, syrup and peanut butter into a large, heavy pan. Heat gently, stirring frequently until everything has melted & combined to form a deep golden liquid

Take off the heat. Stir in the vanilla extract and the oats until thoroughly combined

Spoon approximately half of the oaty mixture into the tin and push down firmly to completely cover the base

Spread the jam (jelly) over the oats

Carefully top the jam with the remaining oat mixture - use a spoon to put small dollops across the jam and spread out using the back of the spoon. Ensure that all of the jam is covered to prevent it from bubbling up and that the oats are firmly pressed down

Bake for 25-30 minutes until golden

Remove from the oven and allow to cool for 15 minutes. Using a sharp knife, mark out portions on the flapjack. Run the knife around the edge of the flapjack to loosen it from the sides of the baking tin

When completely cold, remove from the tin and cut out the marked portions

Store for up to 3 days in an airtight tin