PREPARE cornbread mix according to package directions, except bake in a 10 1/2-inch cast iron skillet (cornbread will be thin). Remove cornbread from skillet; cool and cut into cubes. Wipe out skillet with paper towels; spray generously with no-stick cooking spray.
HEAT oven to 350°F. Place cornbread cubes in skillet. Top with turkey, ham and cheese. In medium bowl, whisk together eggs, milk, mayonnaise, 1 tablespoon mustard, salt and pepper until well blended. Pour evenly over ingredients in skillet. Bake 30 to 35 minutes or until set and lightly browned.
MELT currant jelly by warming slightly. Add 1 tablespoon honey mustard; whisk to blend.
REMOVE skillet from oven. Cut in wedges, sprinkle with powdered sugar and serve with currant jelly and mustard sauce.