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.