Firstly mix the warm milk (200 ml initially) with yeast and a pinch of sugar and a sprinkle of flour on top (so you can see how much has the yeast risen) and let it rest in a warm place for about 10 minutes. Separately, mix the flour with the remaining sugar, salt and xanthum gum, now make a hole in the middle and add the wet ingredients: eggs yolks, vanilla essence, soft butter and the fruit peel, followed by the risen yeast (now that the flour has bubbled up)! Pour it over and knead to a smooth dough, it should take about about 5 minutes.