To make the crepe batter, in a blender, combine the egg, milk, vanilla, all-purpose flour, whole wheat flour, salt and oil and blend until smooth, about 1 minute. Refrigerate the batter at least 30 minutes before making crepes. (For extra-tender crepes, refrigerate overnight.) To make the filling, in a large sauté pan over medium heat, melt the butter. When the butter stops foaming, add the apples and granulated sugar and cook, stirring occasionally, until the apples are tender and golden, 5 to 7 minutes. Add the caramel sauce and cook until the sauce starts to boil, then remove the pan from the heat. Warm a 10-inch steel crepe pan over medium heat. Melt 1 tsp. butter in the pan and use a paper towel to coat evenly, wiping out excess butter. The pan is hot enough when a droplet of water flicked onto the surface of the pan immediately sizzles and beads around the surface. Lift the pan from the heat at a slight angle, pour about 1/4 cup batter into the center, and quickly tilt and turn the pan in a circular motion to spread the batter evenly to the edges. (If the batter does not cover the entire surface of the pan, drip extra batter into the empty spaces.) Return the pan to the heat and cook until the crepe is golden underneath, about 2 minutes. With a spatula, flip the crepe and cook about 1 minute more. Transfer the crepe to a warmed plate and cover with a clean, dry cloth. Repeat with the remaining batter to make 8 crepes, stacking them on top of each other. To assemble, lay a crepe flat, spoon 2 to 3 Tbs. of the apple filling into the center, and fold the crepe over the filling to form a triangle. Repeat with the remaining crepes. Divide the crepes among 4 warmed individual plates and dust crepes with confectioners' sugar. Top with whipped cream and serve immediately. Serves 4. Williams-Sonoma Kitchen.