Measure the craisins into a small bowl and top up with the rum. Stir and set aside to soak for a few hours.
Place the starter, milk, sugar, egg, spices, oils and zests, salt and vanilla into the Thermomix bowl and blend 6 sec/speed 6.
Add the 550g of bakers flour and blend 6 sec/speed 6. Check the consistency. It may be a little more sticky than you think you can work with, but keep in mind sticky gives you a much nicer bun in the end. Add a little more flour if you think it is too sticky.
Knead 2 min/dough setting/interval.
Tip out into a large container to prove for up to 12 hours or longer depending on where you are in the world. If your kitchen is cold, you may need longer, if is a warm day, you may need less time. This is a learned thing, you will get better with it over time.
Give a couple of slap and folds throughout the proofing process.
When the craisins have soaked up all the rum, drain any liquid, and add them to the dough and using a few folds, make sure they are well incorporated. You could potentially dust them with a little flour first as this will help them stay in the buns better.
Form into 12-14 buns and place on a tray, cover and prove again.
Make the paste for the crosses by mixing all ingredients in a small bowl until you have a thick pipeable consistency. Transfer to a piping bag or ziploc bag and pipe them on.
Bake in a cold oven set to 180°C for 50 minutes or longer if needed. They should sound hollow when tapped. To prevent them getting too brown, you can place a sheet pan on the rack above to protect them from direct heat.
If you have any reserved soaking liquid, brush it onto the hot buns immediately. Otherwise, use pure maple syrup to glaze.
Serve with the spiced rum butter.
To make the Spiced Rum Butter place all ingredients into the Thermomix bowl and blend 10 sec/speed 6. Stop and scrape down sides of bowl and insert Butterfly. Whip 30 sec/Butterfly/speed 3.
Wrap in baking paper and keep in the fridge or freezer until use.