Dissolve yeast in warm water.
Mix 3 cups of the flour, 2 tablespoons sugar and the salt in a bowl.
Add sour cream and yeast mixture.
Stir well to make a dough.
Turn out onto a floured board and knead until smooth, working in the remaining flour.
Roll out dough into a rectangle approximately twice as long as it is wide.
Spread the 1 cup softened butter over dough, leaving a 1/2 inch margin on all sides.
Fold dough in half from the short end to enclose butter completely.
Roll and pat out dough into a square less than 1/2 inch thick.
Fold the corners into the center, like an envelope; refrigerate 30 minutes.
Repeat this rolling and folding 3 more times, refrigerating each time.
Dust board with flour as necessary to prevent sticking.
Divide dough in half.
Roll out one half into an 18 x 10-inch rectangle.
Brush with half of the melted butter and sprinkle with half the sugar and cinnamon.
Spread on half the jam.
Starting from the long side of the rectangle, roll up dough like a jelly roll.
Transfer dough to a greased baking sheet, curving the ends around to form a circle.
Moisten the seam with water to seal.
With scissors, make an even number of cuts at 1/2 inch intervals across the top of roll, cutting about 3/4 of the way down into the roll.
Pull every other slice to the outside of the circle and turn on its side; pull each remaining slice to the inside and turn on its side in the opposite direction.
Roll out the other half of dough, fill and repeat the procedure.
Cover with a dish towel and let pastry rise in a warm place about 45 minutes or until doubled in bulk.
Bake in a preheated 325° oven about 40 minutes or until golden