In small bowl, mix together the honey, mustard and horseradish.
Remove corned beef from packaging and rinse in cool water. Pat dry. Place in a gallon sized Ziploc bag. Smear the honey/mustard mixture over the corned beef being sure to coat the entire thing. Add spice mixture to bag and seal.
Gently massage the corned beef for a few second to be sure the marinade is coating every surface possible. Place on plate and put in fridge to marinate for 3 hours or overnight.
Preheat oven to 350.
Place corned beef, fat side up, on top of a large square of aluminum foil. Pour a little of the excess marinade on top. Sprinkle 2 Tbs brown sugar over the corned beef.
Bring up edges of foil and seal to make a loose packet around the meat. Place in a shallow roasting pan and bake at 350 degrees for 2 hours.
Remove from oven and carefully vent a corner to let steam escape.
Turn oven to broil. Fold sides of foil down a bit to expose the corned beef. Pop back into oven and broil 1 -3 minutes until top is deep brown and sizzling.
Remove to platter and slice against the grain, serve slice with a spoonful of the pan drippings for a sweet/spicy kick.
Recipe by A Hen's Nest - NW PA Single Woman Mom Blog at https://ahensnest.com/2012/03/sweet-spicy-foil-roasted-corned-beef-recipe.html