In a saucepan, combine the sour cream, sugar, butter and salt. Cook over low heat until butter is melted and mixture is well combined. Set aside to cool.
Proof the yeast in a small bowl with the water and stir to combine until the yeast is well dissolved. Stir in the sugar and set aside. Add the yeast mixture to the sour cream mixture along with the eggs and combine well.
Transfer the mixture to a stand mixer and on medium speed add the flour 1 cup at a time until a soft dough forms; you may not need all the flour. The dough should not be sticky. Transfer the dough to a work surface and knead it for about 5 minutes or until it is smooth and not sticking to your hands. Transfer the dough to a buttered bowl; cover and let rise until doubled in bulk, about 1 hour.
Punch down the dough and roll it out into a 12 x 20 inch rectangle. Spread the melted butter evenly over the dough. Stir the cinnamon and sugar together in a small bowl and sprinkle it evenly over the surface of the dough. Roll the dough up like a jellyroll starting at the longest side near you. Pinch the seam and ends closed and place the dough on a parchment lined baking sheet. Bring the two ends together and pinch them closed. Cover and let rise for 30 minutes.
Preheat oven to 375F
Bake the cake until golden brown, about 25 minutes. While cake is baking, make the glaze.
For the glaze, whisk the confectioners sugar and enough Half/Half or milk in a bowl to make a smooth glaze consistency; stir in vanilla extract. Frost the top of the cake and sprinkle the colored sugars in alternate rows over the frosting.