In a medium bowl, whisk together the eggs and milk. Whisk in the salt, sugar, and flour. Set aside for 30 minutes. In a nonstick 8 to 10-inch skillet, melt about 1/2 teaspoon butter over medium heat. When it foams, pour or ladle about 1/8 cup (2 tablespoons) into the batter. Lift and swirl the pan so the batter coats the bottom. Replace the pan on the burner and cook just until set and the underside is lightly browned. Using a spatula or your fingers, flip and cook until the other side is lightly browned. Transfer to a platter. Repeat until the batter is used up.
In a food processor blend together the 12 tablespoons butter, sugar, orange rind, and juice. Chill. When ready to serve, melt the orange butter in a saute pan over an open flame to make a sauce. Add the crepes one at a time using a fork to flip them to coat both sides. When coated fold the crepe into quarters, push it to the side of the pan and continue coating another one. Overlap the folded crepes on one side of the pan while you coat the rest. When all of them have been dressed in the orange butter, pour the orange liqueur and cognac into the pan and warm it, then tip your pan towards the flame to ignite it. Let the flame die down and serve 2 crepes per person.