Preheat the oven to 350°F. Spray a 1 ½ quart baking dish with cooking spray. Set aside.
In a medium-size mixing bowl using an electric mixer, cream together mayonnaise, Thousand Island, and cream cheese until fully combined.
Squeeze all excess moisture from sauerkraut. Add to the bowl with corned beef and 1 ½ cups cheese. Mix by hand until combined.
Spread evenly in dish. Sprinkle with remaining cheese.
Bake for 30 minutes or until bubbly and golden. Garnish with chopped chives. Serve immediately with rye bread, crackers or crostini for dipping.