Preheat the oven to 350 degrees and then spray a 9x13 inch pan with cooking spray.
Cut the Hawaiian Rolls in half with a bread knife and separate the tops from the bottoms.
Add the bottoms to the greased pan and then layer in corned beef. Use 1/2 to 1 slice of corned beef per roll.
Add on about 1 Tbsp. to 1 1/2 Tbsp. of sauerkraut to each sandwich.
Fold the Swiss cheese in half and then quarter it. Add two quarters to each roll.
Using a butter knife, spread Thousand Island Dressing on the top of each bun and then place it on the sandwich.
Mix melted butter, garlic powder and onion powder. Then brush the top of each sandwich. Sprinkle with sesame seeds or poppy seeds.
Lightly cover with tin foil and bake for 10 minutes. Then remove tin foil and bake another 10 minutes.