1Thaw blueberries as directed on bag; drain, reserving liquid. In medium bowl, mix cottage cheese, sugar, lemon peel, nutmeg, cinnamon, cream cheese and yogurt until well blended. Gently stir in drained blueberries.
2Place large sheet of waxed paper on work surface. For each blintz, place 1 flour tortilla on waxed paper. Spoon about 1/3 cup yogurt mixture in center. With pastry brush, moisten outer edge of tortilla with reserved blueberry liquid. Fold opposite sides of tortilla over filling, ends meeting in center; fold remaining 2 sides of tortilla over each other.
3In 12-inch nonstick skillet, melt 1/2 tablespoon of the butter over medium heat. Cook 4 blintzes at a time, seam side down, about 2 minutes on each side until golden brown. Place blintzes, seam side down, on serving platter; drizzle with syrup. Sprinkle with powdered sugar; garnish with lemon slices.