For the flapjack base and filling, preheat the oven to 180°C/Fan 160°C/Gas 4 and line a 20cm square baking tin with nonstick baking paper.
In a large saucepan, melt the butter, sugar, golden syrup or honey and almond extract over a low–medium heat until the sugar has dissolved and the mixture is smooth. Do not boil or overcook the mix.
Turn off the heat, then stir in the oats and ground almonds until they’re fully coated. Pour half the mix into your prepared tin and smooth it out with a metal spoon or rubber spatula.
Spread over the cherry jam or compote for the filling, then top with the remaining flapjack mix and smooth it out gently, making sure the jam is fully covered. Bake for 15-20 minutes. It should still be very wobbly when it comes out with golden brown edges. This is the key to soft, gooey flapjacks, so make sure you don’t overbake. Leave the flapjack to cool to room temperature in the tin. This usually takes about 2 hours, but it may take longer.
For the topping, pour the melted white chocolate onto the cooled flapjack and spread it out to the edges. Give the tin a light shake to smooth out the chocolate, then dollop the jam or compote over the chocolate and gently swirl it through with a knife or skewer to create a pretty pattern.
Leave to cool to room temperature or refrigerate for about 1 hour until the chocolate has fully set. If you put it in the refrigerator, take it out about 15 minutes before slicing and use a hot knife to cut through the flapjack so the chocolate is less likely to crack. Cut into 16 squares and enjoy! Store in an airtight container at room temperature for up to 5 days.