Total time: 4 hours (with resting time)
In a saucepan, heat the milk and fresh baker's yeast to 37°C to activate the ferments. Mix until the yeast has completely dissolved.
Add 100 g of flour and mix until the dough is smooth.
Place the dough in a mixing bowl, cover with a tea towel and leave to rise for 1 hour.
Rehydrate the raisins in a bowl of hot water with the rum (optional).
Put the rested dough, the remaining 200 g flour, sugar, salt, whole eggs and yolk into the bowl of a food processor with a kneading attachment. Knead for about 10 minutes.
Add the butter and knead for 10 minutes, adding the drained raisins a few at a time.
Grease a Kouglof mould generously with butter and place an almond in each of the grooves. Spread the dough evenly in the mould.
Leave to rise for 3 hours.
Preheat the oven to 180°C and bake for 45 minutes.