For the puree, cook the potatoes for about 20 minutes until soft, drain, peel and mash with a fork until the puree is smooth.
Add 60 g soft butter while the potatoes are still warm. Add egg, 1⁄8 l milk, buttermilk and yeast, mix well.
650 g flour, 35 g sugar, 3⁄4 tsp salt and raisins in a bowl. Add mashed potatoes. Mix everything well with the dough hooks of the mixer. Then knead vigorously on the work surface for about 5 minutes until the dough is smooth and elastic.
Put back into the buttered bowl, cover with a damp tea towel and leave to rise for about 1 hour until the dough has doubled.
Butter the bottom and rim of a springform pan (26 cm Ø). Melt the syrup and 60 g butter together in the microwave or on the stove. Mix 4 tablespoons sugar and cinnamon. When the dough has risen for about 1 hour, box it down.
Roll out on the floured work surface to a thickness of 2 cm to form a rectangle of approx. 35 x 30 cm. Brush with butter syrup, leaving 1 cm free at each edge. Spread the cinnamon sugar evenly over the syrup.
And this is how the Cinnamon Rolls are made: Roll the dough evenly and firmly, like a carpet. Cut off 3-4 cm thick slices with a very sharp knife. Place them close together in the mould.
The space should be just enough for all the discs. Cover and leave to rise for another 30 minutes.
Preheat oven (electric cooker: 190 °C/circulating air: 165 °C/gas: see manufacturer). Bake Cinnamon Rolls for approx. 30 minutes until they are golden brown. Then allow them to rest for 10 minutes before you put them out.
Mix 2 tablespoons of milk and icing sugar. Spread the pastry with the icing. Separate the individual Cinnamon Rolls with a knife. Try to keep the size and shape of the original rolls.