Tarte Tatin | America's Test Kitchen

Ingredients

• 1 1/3 cups unbleached all-purpose flour , plus extra for work surfaces
• 1/4 cup confectioners' sugar
• 1/2 teaspoon table salt
• 8 tablespoons unsalted butter (1 stick), chilled and cut into 1/4-inch pieces
• 1 large egg (cold), beaten
• 8 tablespoons unsalted butter (1 stick)
• 3/4 cup granulated sugar , plus 1 tablespoon
• 3 pounds (1361 grams) Granny Smith apples (about 6 large 8-ounce [227 grams] apples), peeled, quartered, and cored
• 1 cup heavy cream , cold
• 1/2 cup sour cream , cold