Preheat the oven to 170°C /150°C/ gas mark 3 and grease and line a 20cm square cake tin.
Weigh out 200g of the oats and tip them into a food processor. Pulse them gently so they break down into a finer oat crumble, but not as powdery as oat flour. Set aside for a moment.
Melt the butter in a large saucepan over a low heat then pour in the golden syrup and sugar.
Stir together until the sugar has melted.
Remove from the heat and add the rolled and pulsed oats, pumpkin and sunflower seeds and salt. Stir until well combined.
Transfer the flapjack mixture to the fridge for 30 minutes to cool down slightly.
Remove from the fridge then stir in the chopped white chocolate and raspberries, reserving a small handful.
Pour the flapjack mixture into the tin and press down evenly.
Scatter the reserved raspberries and chocolate chips over the top, pressing down into the surface.
Bake in the oven for 40 minutes.
Remove from the oven. Run a palette knife around the edges to loosen them from the tin then leave to cool in the tin.
Once cool, remove from the tin and cut into squares.
Make the chocolate glaze, pour over the chocolate.