In a bowl, stir the yeast in the milk to dissolve.
Mix the flour with salt. Make a hole in the center and pour in the yeasted milk. With a spoon, draw little flour to the milk and cover with a towel for 25 minutes.
Mix the flour from the side to form soft dough.
Put the dough on a floured working surface. Knead until smooth for about 20 minutes.
Place the dough in an oiled bowl. Cover with a towel and let it rise until double for one hour.
Press down on the dough with one hand for 1 second. Rest for 10 minutes.
Grease with butter, a deep cake tin about 20 cm across 15 cm. Knead 100 grams butter, egg yolks, sugar, sultana, nutmeg, lemon and orange rind and vanilla until combined.
Shape the dough into round, place in the tin, cut an X across the top. Cover with a towel and let rest for two hours.
Brush the top with the egg glaze and bake in the oven at 200 degrees C. for 45 minutes. Remove from the tin and leave to cool. Dust with powdered sugar.