Salt and Pepper Biscuits

Name: Salt-and-Pepper Biscuits
Ingredients: 3/4 cup sour cream; 4 tablespoons heavy cream, divided; 1 tablespoon baking powder; 1 teaspoon kosher salt; 1 teaspoon sugar; 1/2 teaspoon coarsely ground black pepper plus more; 2 cups all-purpose flour plus more for surface; 6 tablespoons (3/4 stick) chilled unsalted butter, cut into pieces; Flaky sea salt (such as Maldon); Salt-and-Pepper Butter (optional); A 2 1/4-diameter biscuit or cookie cutter