Preheat the oven to 180°C, gas mark 4. Grease and line a 20cm square tin.
Place the butter, sugar, syrup and 2 tbsp of marmalade in a large saucepan and heat until melted and bubbling. Off the heat, stir in the oats, apricots, sultanas and pumpkin seeds.
Pour into the tin and spread out into an even layer. Bake for 20-25 minutes until golden. Allow to cool before removing from the tin.
Warm the remaining marmalade and brush over the flapjacks before cutting into 16 pieces.