So here's the recipe I obtained last year (can't remember where from) and can recommend it completely. For a bit of extra kick, add in more ginger (I'm pretty liberal with it myself). As said before it's really lovely mixed in with porridge....mmmmm. If you want something more spreadable, chop up everything quite small.
1 3/4 kg marrow (peeled, seeded and cubed)
1 1/2 kg sugar (I use demarera)
225g dried apricots (chopped)
2 level tablespoons ground ginger
4 lemons (juice of) - I use the bottled juice and guess how much
*Layer the marrow cubes and sugar in a large non-metallic bowl. Cover with a clean tea towel and leave to stand for 2-3 hours
*Put the marrow and juices in a large preserving pan with the apricots and ginger
*Slowly bring to the boil, stirring occasionally to dissolve the sugar
*Add the lemon juice and reduce the heat
*Simmer for 1-1.5 hours until the marrow is translucent and the syrup is thick
*Pack into warm sterlised jars and seal