Heat sour cream over low heat, stir in sugar, salt and butter, cool to lukewarm. Sprinkle yeast over warm water in a large mixing bowl, stirring until yeast dissolves. Add sour cream mixture, eggs & flour. Mix well. Cover tightly and refrigerate overnight.
The next day, make cream cheese filling by combining cream cheese and sugar in a small bowl. Add egg, salt and vanilla and mix well.
Then make the glaze by combining all ingredients in a small bowl.
Then, divide dough into four even parts. Roll each part on a well-floured surface into a 12x8 in rectangle. Spread 1/4 of cream cheese filling on each rectangle, roll up jelly roll style beginning at long side. Pinch edges together and fold ends under slightly. Place rolls seam side down on a greased baking sheet. Slit each roll at 2 inch intervals about 2/3 of way through dough to resemble a braid cover and let rise in a warm place free from draft until double in size (about 1 hour). Bake at 375 for 12-15 minutes. Spread with glaze while warm.