Place cottage cheese in a blender or food processor, and process until smooth, scraping sides of processor bowl once. Add cream cheese, sugar, and 1 teaspoon vanilla; process until smooth. Pour mixture into a bowl; cover and chill.
Place flour in a medium bowl. Combine milk, oil, 1 1/2 teaspoons vanilla, salt, and eggs, and add to flour, stirring with a whisk until almost smooth. Cover and chill 2 hours.
Place a 10-inch crepe pan or nonstick skillet coated with cooking spray over medium-high heat until hot. Remove skillet from heat. Pour 3 tablespoons batter into pan; quickly tilt pan in all directions so batter covers skillet with a thin film. Cook about 1 minute.
Carefully lift edge of crepe with a spatula to test for doneness. The crepe is ready to turn when it can be shaken loose from the pan and the underside is lightly browned. Turn crepe over; cook 30 seconds on other side.
Place crepe on a towel; cool. Repeat procedure with remaining batter. Stack crepes between single sheets of wax paper or paper towels to prevent sticking.
Spoon 3 tablespoons cottage cheese mixture in center of each crepe; fold sides and ends of crepe over filling to form a rectangle. Place filled crepes, seam sides down, on a baking sheet lined with plastic wrap. (Blintzes may be covered and chilled at this point).
Place a large nonstick skillet coated with cooking spray over medium heat until hot. Place 4 blintzes, seam sides down, in skillet; cook 2 minutes or until lightly browned. Turn blintzes over; cook for 2 minutes. Repeat procedure with remaining blintzes. Serve warm with blueberries, and sprinkle with powdered sugar.