In large bowl of mixer, mix 1 c flour, 1/3 c sugar, and ¾ t salt. Dissolve 2 pkg yeast in 1/3 c warm water. Combine 1/3 c milk and 6 T margarine in saucepan. Heat to warm, margarine does not need to melt. Add milk and yeast to flour mix and beat two minutes at medium speed. Add 1 egg and ½ c flour. Beat at high speed 2 minutes more. Stir in up to 1 ¾ c more flour to make a soft dough. Cover and let rise till double, about 50 minutes.
Cheese filling: Beat 3 oz cream cheese until light and fluffy. Add 1 egg, ¼ c sugar, and ½ t vanilla. Beat till blended.
Push down dough. Roll out to 18” circle. Lay over a greased 6-cup ring mold. Fit dough into bottom and sides, leaving about 1” hanging over edges. Pour in cheese filling and lap over dought from edges over filling. Cut a cross through the dough over center ring, forming triangles. Fold dough back over filling. Cover. Let rise till doubled, about 50 minutes. Bake at 350 for about 30 minutes. Remove from pan and cool on rack. Frost while warm with confectioners sugar glaze made with lemon juice.