Melt 2 tablespoons of butter over medium-high heat in a 7-quart Dutch oven or large stockpot. Add the chopped onions, celery, and carrots and cook for 3 to 4 minutes until the onion is translucent. Season the vegetables with garlic powder, onion powder, dried thyme, salt, and pepper.

Melt the remaining 4 tablespoons of butter in the pot with the vegetables and add the flour. Cook the flour with the butter, while stirring, for 2 to 3 minutes until it reaches a light golden brown color.

Slowly add the chicken stock and heavy cream while stirring so that lumps do not form. Stir the shredded chicken into the soup, reduce the heat to medium-low and simmer the soup while you make the dumplings.

Whisk together the flour, baking powder, salt, and black pepper in a medium mixing bowl until combined. Add the sliced butter and rub it into the flour between your thumb and index fingers until it resembles coarse crumbs. Add ⅔ cup of buttermilk and mix the dough with a wooden spoon. Add up to ⅓ cup more buttermilk until all of the flour is moistened and the dough starts to stick together.

Shape the dough into a ball using your hands. Use a 1 ½ to 2 tablespoon cookie scoop to scoop out balls of dough and place them on top of the simmering soup, one at a time spaced evenly apart. Once all of the dumplings have been added, cover the soup and simmer it for 10 minutes to cook the dumplings.

Remove the lid and check a dumpling by cutting it in half to see if it is cooked through. If you see raw dough in the middle, cover the pot and continue to cook the soup for another two minutes until the dumplings are cooked through.

Remove the pot from the heat, allow the soup to cool slightly, and ladle into bowls. Garnish the soup with fresh chopped parsley and enjoy!