Place diced russet potatoes in a large pot and pour in the chicken broth. Bring to a boil over medium-high heat, then reduce to a steady simmer. Cook uncovered for 15 minutes until potatoes are completely fork-tender.

In a small bowl, whisk the flour with 3 to 4 tablespoons of the heavy cream until completely smooth with no dry flour streaks remaining.

Add butter to the pot and stir until melted. Slowly pour in the flour and cream mixture while stirring constantly. Continue stirring for 1 to 2 minutes until the broth visibly thickens.

Pour in the remaining heavy cream and stir to combine. Simmer gently for 5 minutes, stirring occasionally, until the soup thickens further and coats the back of a spoon.

Reduce heat to low. Add sour cream, shredded cheddar, garlic powder, onion powder, salt, and pepper. Stir slowly until the cheese is fully melted and the soup is smooth. Do not boil after adding sour cream.

Ladle into bowls and garnish with extra shredded cheddar, crumbled bacon, sliced green onions, and sour cream. Serve immediately with crusty bread.