Dissolve the yeast in the warm milk and place in the bowl of the mixer. Add the butter, flour, egg yolks, Caster Sugar and a pinch of salt. Beat well until a homogeneous dough is formed. Remove the dough from the mixer bowl, roll it and place it in a bowl. Cut a cross on top, cover with a damp cloth and let rise until doubled in size.

Knead the dough again and roll it out into the shape of a rectangle on a counter sprinkled with flour.

For the filling: Spread the dough with the softened butter and sprinkle with the Golden Granulated sugar and cinnamon to taste, leaving a 3-4 cm border on one end. Roll up the dough, ending with the side with no filling. Cut crosswise into slices.

Arrange the slices on baking tins sprinkled with flour. Cover with a damp cloth and let the dough rise about another 20 minutes. Bake in the oven for 25 to 30 minutes or until done. Remove from oven, let cool and serve. Sprinkle with Icing Sugar and more ground cinnamon if desired.