Whipped Potatoes with Horseradish

Name: Whipped Potatoes with Horseradish
Ingredients: 2 tablespoons unsalted butter, melted, divided, plus 1/2 cup (1 stick), cut into 1-inch cubes, room temperature; 2 1/2 pounds russet potatoes, peeled, cut into 2-inch pieces; Kosher salt; 4 ounces cream cheese, cut into 1-inch cubes, room temperature; 2 tablespoons prepared horseradish; 2 /3 cup whole milk, warmed; Freshly ground black pepper; 1 bunch scallions, white and pale-green parts only, minced (about 2/3 cup loosely packed); Hungarian sweet paprika