Combine yeast and water in a small bowl, stirring until dissolved, and set aside until yeast is proofed.
In a large mixing bowl combine the milk, sugar, and butter, stirring until dissolved.
Add the salt, eggs, and yeast mixture and blend thoroughly.
Beat in 3 cups of flour to make a smooth batter Add additional flour to make a soft dough (dough will be very sticky)
Turn out onto a floured board and knead approximately 8 minutes or until smooth and elastic, adding more flour as needed.
Round into a ball and place in a warm buttered bowl, turning to lightly coat top with some of the butter.
Cover loosely with plastic wrap and let rise until doubled.
Punch down the dough and flatten into a long oval
Spread the jam or marzipan in the oval and then roll into a rope
Join ends together leaving large oval hole in the middle.
Cover and let rise until double, about 1 hour.
While the bread is rising, preheat oven to 350°F.
Bake rings for 30 minutes in the preheated oven or until golden brown and sound hollow when thumped.
Remove and let loaves cool on wire racks.
Icing: Mix all the icing ingredients together until fluffy and well blended.
To serve, frost cooled loaves with icing.
Decorate with different coloured sugars or candied fruit.