Line a square baking tin with baking paper and preheat the oven to Gas mark 4 or 180 degrees.
Mix together porridge oats, butter, flour, baking soda, sugar and golden syrup in a large bowl until it forms an oat-based dough.
Place two-thirds of the mixture in the baking tin and flatten. Bake for 8 minutes.
Remove from the oven and spread with a generous layer of jam.
Crumble the remaining third of the oat-based dough on top of the jam, and dot with frozen raspberries and roughly chopped dark chocolate.
Bake for 20 minutes, then cool. Sprinkle with any leftover chocolate then place in the fridge for a couple of hours before slicing into bars.