Put the butter and milk into a microwave safe bowl or cup and heat in the microwave until the butter has melted. Set aside to cool. In a small bowl, whisk the eggs and set them aside. Sift the flour and salt together in a large mixing bowl and once mixed together, make a well in the center.
Next you will pour about ⅔ of the milk and butter mixture into the well and whisk to combine. The batter will be thick and lumpy but that’s ok. Now you will mix in the eggs and then pour in the remaining butter and milk mixture, whisking until the batter is smooth and there are no lumps.
Let the batter rest in the fridge covered for about an hour. Once the batter has rested, heat a non-stick skillet on medium heat. Once hot add non stick spray or a bit of melted butter so it doesn't stick.
Using a ladle, scoop up about half a ladles worth of batter and pour into pan, and tilt the pan around in a circle to spread the batter into a thin layer. Cook for a couple of minutes until the edges start to crisp and lift up.
You can cool 1 more minute until middle is no longer wet, or carefully use a spatula to flip to other side for 1 minute if you want golden brown on both sides.
Remove and continue on with remaining batter.
Lay down 1 crepe and spread a spoonful of mascarpone cheese over the crepe (if making monte cristo version, cream cheese works for regular ham and cheese). Then sprinkle on some cheddar cheese.
Next lay down 2 or 3 slices of ham. Top with some cooked scrambled eggs if you like. Fold one half of the crepe onto itself so the edge is touching the middle and then pull the other side over and wrap it around.
If desired, place the crepe into a medium heat skillet and grill to melt the cheeses. Place the crepe on your plate and spoon some jam over the top (for monte cristo on top and dust with powdered sugar).