Pre-heat the oven to 325 degrees. Using kitchen shears, cut the hamburger bun into bite sized cubes (about 25). Melt a tablespoon of the butter and toss the cubes in it until coated. Sprinkle a pinch of garlic powder and another of salt over the bread cubes. Lay the cubes in a single layer on a baking sheet and bake in the oven for 15 minutes until they have a crouton texture. Set aside.

In a large pot, bring the remaining ½ tablespoon of light butter over medium heat. Add the celery and onions and cook for about 4 minutes. Add the garlic and cook another minute until vegetables are softened. Remove vegetables to a side plate.

Keep the pot over medium heat and add the ground beef, breaking it up with a spoon or spatula. Sprinkle the meat with the hamburger seasoning and continue cooking until browned.

Add the vegetables to the meat in the pot along with the broth, cheese soup, half and half, yogurt, and about 1/2 cup of the shredded cheese. Stir the mixture together until well combined and increase the heat to high. Once the mixture starts to bubble, reduce the heat to a simmer (low) and let simmer for 20 minutes. Serve topped with remaining cheese and reserved croutons.