1. Weigh or lightly spoon flours and cornstarch into dry measuring cups; level with a knife. Combine flours, cornstarch, 2 teaspoons sugar, and salt in a medium bowl; stir with a whisk. Place milk, melted butter, vanilla, and eggs in a blender; process 15 seconds. Add flour mixture; process 1 minute or until smooth.
2. Heat a 10-inch crepe pan or nonstick skillet over medium heat. Coat pan with cooking spray. Remove pan from heat. Pour a heaping 2 tablespoons batter into pan; quickly tilt pan in all directions so batter covers pan with a thin film. Cook 45 to 50 seconds.
3. Carefully lift edge of crepe with a spatula to test for doneness. Turn crepe over when it can be shaken loose from the pan and the underside is lightly browned; cook 25 to 30 seconds.
4. Place crepe on a towel; cool. Repeat procedure with remaining batter, stirring batter before making each crepe. Stack crepes between layers of wax paper or paper towels to prevent sticking.
5. Combine strawberries, banana, Grand Marnier, and 1 teaspoon sugar in a medium bowl; toss gently to coat.
6. Fold each crepe in half, then in half again to form a triangle. Spoon fruit mixture over crepes; top with a dollop of yogurt.