Cheese-Filled Coffee Cake
["2 pkg. yeast", "1/2 c. warm water", "1 c. butter", "5 c. flour", "1 1/4 c. sugar", "1/2 tsp. salt", "6 egg yolks", "1 c. sour cream", "1 (8 oz.) pkg. cream cheese", "2 whole eggs", "1 tsp. vanilla", "10 oz. apricot jam", "powdered sugar"]
["Dissolve yeast in water.", "Mix flour, 3/4 cup sugar and salt. Beat egg yolks and blend in sour cream, butter and yeast. Stir this egg yolk mixture into flour to make a soft, smooth dough. Knead for 5 minutes on floured surface. Put in a bowl; cover.", "Let rise until almost double."]
["yeast", "warm water", "butter", "flour", "sugar", "salt", "egg yolks", "sour cream", "cream cheese", "eggs", "vanilla", "apricot jam", "powdered sugar"]