In a large bowl, toss butter with 3 cups flour until well coated; refrigerate for 1 hour or until well chilled. In another large bowl, combine yeast and 1-1/2 cups flour. In a saucepan, heat the cream, sugar and salt to 120°-130°. Add to yeast mixture. Beat in egg. Beat on medium for 3 minutes. Stir in chilled butter mixture just until combined (butter will remain in large pieces).
Turn onto a well-floured surface; gently knead 6-8 times. Coat rolling pin with remaining flour. Roll dough into a 21x12-in. rectangle. Starting with a short side, fold dough in thirds, forming a 12x7-in. rectangle. Cover and refrigerate for 1 to 1-1/2 hours or until firm but not stiff.
Turn dough onto a well-floured surface; roll into a 21x12-in. rectangle. Starting with a short side, fold dough in thirds, forming a 12x7-in. rectangle. Give dough a quarter turn; roll into a 21x12-in. rectangle. Fold into thirds, starting with a short side. Repeat, flouring surface as needed. (Do not chill dough between each rolling and folding.) Cover and refrigerate for 4-24 hours or until firm.
For filling, in a small saucepan, bring fruit and water to a boil. Remove from the heat. Cover and let stand for 5 minutes; drain. Stir in the walnuts, brown sugar, flour and cinnamon; set aside.
Cut dough in half lengthwise. Roll each portion into a 12-in. square; cut each square into nine 4-in. squares. Spoon about a rounded tablespoonful of filling onto the center of each square. Brush edges of dough with water; fold dough diagonally in half, forming a triangle. Press edges to seal. Place 4-in. apart on greased baking sheets. Cover and let rise in a warm place until doubled, about 1 hour.
Bake at 375° for 16-18 minutes or until golden brown. Remove to wire racks. Combine icing ingredients until reaching desired consistency; drizzle over warm turnovers.