Step 1Measure powdered sugar into small bowl or covered container. Bury vanilla bean in the middle; cover and let stand overnight.
Step 2Meanwhile, combine flour, granulated sugar, baking powder and salt in bowl. Stir together milk, egg substitute, butter and vanilla. Stir liquid ingredients into dry ingredients just until blended. Strain through fine mesh strainer. Refrigerate overnight.
Step 3Stir batter. Brush a 10-inch nonstick skillet with oil or spray with nonstick cooking spray and heat over medium heat. Pour about 3 tablespoons batter into pan. Rotate and tip pan quickly so batter evenly covers bottom of crepe pan. Cook a few minutes until browned then turn and cook a few seconds, just until set. Remove and keep warm while cooking remaining crepes.
Step 4Spread about 2 tablespoons chestnut puree over half of each crepe. Fold into quarters and arrange on plate. Spoon vanilla sugar into a small strainer and sift over top of crepes to taste. Sprinkle with grated chocolate.