Peel the potatoes, rinse in cold water and cut into fourths. Place the potatoes in a large pot and cover with water. Bring to a boil and cook until fork-tender, 20 to 25 minutes.
Meanwhile, add the butter to a saucepan over medium heat. Allow the butter to brown, 2 to 3 minutes, being careful not to burn it. Swirl the pan as you go, stopping when the solids turn medium to deep golden brown.
Drain the potatoes, then return them to the pot. With the burner on low heat, mash the potatoes with a potato masher; the more steam that's released while you mash, the better. Mash for about 5 minutes. Turn off the burner.
Add the cream cheese, half-and-half, cream, some salt and pepper and three-quarters of the brown butter to the pot and stir to combine. If the mixture needs thinning, add some milk. Check the seasonings, adding salt and pepper to taste. Drizzle the remaining brown butter over the top. Sprinkle with fresh parsley.