Bake the potatoes in advance (either in the oven at 400°F for 45-50 minutes or in the microwave for 10-12 minutes). Let them cool slightly, peel, and roughly mash them. Set aside.

In a large pot or Dutch oven, melt the butter over medium heat. Whisk in the flour to create a roux. Stir continuously for 1-2 minutes until the mixture turns golden and no raw flour smell remains.

Gradually whisk in the chicken or vegetable broth, followed by the milk and heavy cream. Keep stirring to ensure no lumps form.

Add the garlic powder, onion powder, salt, and pepper. Bring the mixture to a gentle simmer.

Stir in the mashed potatoes. Use an immersion blender if you prefer a smoother soup or leave some chunks for texture. Add 1 cup of shredded cheddar cheese, stirring until fully melted and incorporated.

If the soup is too thick, add more broth or milk until your desired consistency is achieved.

Ladle the soup into bowls. Top with crumbled bacon, additional shredded cheese, sour cream, and chopped green onions.