HEAT oven to 425° F. Lightly butter a baking sheet.
SPREAD 1/2 teaspoon mustard on each slice of raisin bread.
LAYER between mustard sides of two slices of bread, 1 slice cheese, 2 slices ham, and another slice of cheese. Repeat to make four sandwiches.
WHISK eggs, flour, butter, salt and pepper in a shallow dish until smooth. Blend in milk.
DIP both sides of sandwiches into egg mixture until bread is lightly soaked. Place on baking sheet; drizzle any remaining egg mixture over top of sandwiches.
BAKE 8 to 10 minutes until bottom is golden brown. Turn with wide spatula and continue baking 8 to 10 minutes or until second side is golden brown. Serve warm.