OVEN TEMP: 350 SOFTEN YEAST FROM ROLL MIX IN 1/4 CUP WARM WATER. COMBINE THE MIX AND 1/4 CUP SUGAR. STIR IN THE YEAST, EGG, SOUR CREAM AND BUTTER. MIX WELL. PLACE DOUGH IN GREASED BOWL, TURNING ONCE. COVER AND CHILL 2 TO 3 HOURS. TURN DOUGH ONTO FLOURED SURFACE. ROLL THE DOUGH INTO A 18" CIRCLE. FIT INTO A 6 CUP MOLD RING, ALLOWING SOME DOUGH TO HANG OVER THE EDGES.(DOUGH WILL COVER THE CENTER HOLE.) BEAT CREAM CHEESE, SUGAR AND VANILLA TILL SMOOTH. ADD EGGS, ONE AT A TIME, BEATING WELL AFTER EACH ADDITION. POUR INTO MOLD. BRING DOUGH FROM SIDES OVER THE TOP OF FILLING. SEAL TO CENTER OF MOLD. CUT AN X IN THE DOUGH COVERING THE CENTER HOME. FOLD THE FOUR TRIANGLES BACK OVER TOP OF RING, SEALING TO OUTER EDGES. LET RISE UNTIL ALMOST DOUBLE, 1 TO 1 1/2 HOURS. BAKE 35 TO 40 MINUTES OR UNTIL WOODEN PICK INSERTED INTO FILLING COMES OUT CLEAN. COOL IN THE PAN 10 MIN. TURN OUT ON A RACK, SPRINKLE WITH CONFECTIONERS SUGAR AND SERVE.