Prepare the hot roll mix according to manufacturers instructions, adding the 2 tablespoons of sugar. Cover dough and put in a warm draft free place to rise.
Let rise until doubled, then punch down and divide into three pieces.
Roll pieces of dough out into a circle about 8 or 9 inches in diameter.
Place dough into three greased 8 or 9 inch pans, and let rise until doubled.
In a saucepan over medium heat, combine the prunes and water. Simmer for 5 minutes, then remove from heat and cover. In a small bowl or cup, stir together the remaining sugar and cinnamon. Set aside.
Preheat oven to 375 degrees F (190 degrees C). When the dough has risen, spread the prune puree over the three cakes. Stir sour cream to soften, and spread over the prunes. Dust with the cinnamon sugar mixture.
Bake for 20 to 25 minutes in the preheated oven, until top edges are golden. Cover with more sour cream and cinnamon sugar if desired before serving.
