01 - Whisk flour and salt in a large bowl. Create a well in center, add eggs, and gradually incorporate milk and melted butter until smooth. Rest batter for 10 minutes.
02 - Preheat a nonstick crepe pan or skillet over medium heat. Lightly coat surface with melted butter.
03 - Pour 1/4 cup batter into pan, swirling to create thin, even layer. Cook 1-2 minutes until edges lift and bottom is golden. Flip and cook 30 seconds. Transfer to plate and repeat with remaining batter.
04 - Set oven to 350°F for final baking.
05 - Layer ham slices, spinach, cheese, and crème fraîche on each crepe. Season with black pepper.
06 - Fold crepes into quarters or rolls. Arrange in baking dish and sprinkle remaining cheese over top.
07 - Bake 8-10 minutes until cheese is melted and crepes are heated through.
08 - Serve hot with additional spinach garnish or side salad if desired.