Bring the butter and eggs to room temperature. Mix yeast with milk and 10 grams of sugar in a bowl and dissolve. Allow to stand until bubbles rise (to about 10-15 minutes).
Mix the flour, 20 grams of sugar and salt in another key. Then add eggs to the bowl with yeast and milk, and knead until the dough is smooth, about 10-15 minutes. Next knead butter into the dough, knead for about 10-15 minutes and knead longer until the dough is springy and stretchy. Leave dough covered and give it some time to rise.
Roll out dough into a rectangular sheet of dough about 1 in thick. Brush with Nutella, leaving all around a 1 cm wide edge. Roll up the dough from the long side (bottom seam), press down a bit. Cut 12 (about 3 cm wide) equal pieces.
Grease the muffin tin with butter and flour. Now place the pieces upright, with the cut surface facing upwards, into the trough. Bake in a preheated oven at 180 C (350 F) for approx. 20-25 minutes.
Take the rolls out of the oven, and immediately loosen them on the edge with a knife to remove them from the pan. Then allow to cool for about 5 minutes, and leave to cool on a wire rack.