In a small saucepan, combine the sour cream, sugar, butter and salt. Cook over medium-low heat, stirring constantly, for 5-10 minutes or until well blended. Cool to room temperature.
In a large bowl, dissolve yeast in warm water. Add sour cream mixture and eggs. Beat until smooth. Gradually stir in flour to form a soft dough (dough will be very soft). Cover and refrigerate overnight.
Punch dough down. Turn dough onto a floured surface; knead 5-6 times. Divide into fourths. Roll each piece into a 12-in. x 8-in. rectangle. In a large bowl, combine the filling ingredients until well blended. Spread over each rectangle to within 1 in. of edges.
Roll up jelly-roll style, starting with a long side; pinch seams and ends to seal. Place seam side down on greased baking sheets. Cut six X's on top of loaves. Cover and let rise until nearly doubled, about 1 hour.
Bake at 375° for 20-25 minutes or until golden brown. Remove from pans to wire racks to cool. In a small bowl, combine the confectioners' sugar, milk and vanilla; drizzle over warm loaves. Sprinkle with almonds if desired. Store in the refrigerator. Yield: 20-24 servings.