PreparationFor crepes: Sift flour and salt into large bowl. Whisk milk and eggs in medium bowl. Gradually whisk milk mixture into flour mixture until smooth. Whisk in 2 tablespoons melted butter. Heat crepe pan or 8-inch nonstick skillet over medium-high heat. Brush pan with melted butter. Pour in 2 tablespoons crepe mixture, swirling pan to coat bottom. Cook crepe until golden on bottom and set in center, about 30 seconds. Turn crepe and cook until golden spots appear, about 15 seconds. Transfer crepe to paper-towel-lined ovenproof plate. Repeat with remaining batter, placing paper towels between crepes. Cover tightly with foil. DO AHEAD Can be made 1 day ahead. Chill. For filling and sauce: Bring first 7 ingredients to boil in heavy large saucepan. Reduce heat to low and simmer until rhubarb is very tender, stirring occasionally, about 10 minutes. Add strawberries and Grand Marnier. Remove from heat; let stand 5 minutes. Discard spices. Strain mixture into medium bowl for filling, saving liquid in bowl for sauce. DO AHEAD Can be made 1 day ahead. Cover sauce and filling separately and chill. Rewarm sauce and filling before using. For topping: Whisk all ingredients in medium bowl until peaks form. Preheat oven to 300°F. Heat covered crepes in oven until warmed through, about 15 minutes. Place 1 crepe on work surface. Spread 1 rounded tablespoon warm filling down center of crepe; roll up. Repeat with remaining crepes. Place 3 crepes on each plate. Drizzle with sauce. Top with dollop of whipped crème fraîche.
PreparationFor crepes: Sift flour and salt into large bowl. Whisk milk and eggs in medium bowl. Gradually whisk milk mixture into flour mixture until smooth. Whisk in 2 tablespoons melted butter. Heat crepe pan or 8-inch nonstick skillet over medium-high heat. Brush pan with melted butter. Pour in 2 tablespoons crepe mixture, swirling pan to coat bottom. Cook crepe until golden on bottom and set in center, about 30 seconds. Turn crepe and cook until golden spots appear, about 15 seconds. Transfer crepe to paper-towel-lined ovenproof plate. Repeat with remaining batter, placing paper towels between crepes. Cover tightly with foil. DO AHEAD Can be made 1 day ahead. Chill. For filling and sauce: Bring first 7 ingredients to boil in heavy large saucepan. Reduce heat to low and simmer until rhubarb is very tender, stirring occasionally, about 10 minutes. Add strawberries and Grand Marnier. Remove from heat; let stand 5 minutes. Discard spices. Strain mixture into medium bowl for filling, saving liquid in bowl for sauce. DO AHEAD Can be made 1 day ahead. Cover sauce and filling separately and chill. Rewarm sauce and filling before using. For topping: Whisk all ingredients in medium bowl until peaks form. Preheat oven to 300°F. Heat covered crepes in oven until warmed through, about 15 minutes. Place 1 crepe on work surface. Spread 1 rounded tablespoon warm filling down center of crepe; roll up. Repeat with remaining crepes. Place 3 crepes on each plate. Drizzle with sauce. Top with dollop of whipped crème fraîche.