Mouthwatering Apple Dumplings & Heavenly Cinnamon Sauce

Preheat the oven to 425 degrees F (220 degrees C) and adjust the rack to the lower-middle position. Line a large (at least 18- by 12-inch) baking dish with parchment.

Mix 3 tablespoons of butter, 1/2 cup of brown sugar, 1 teaspoon of cinnamon, and chopped nuts in a small bowl. Spoon a portion of mixture into each hollowed-out apple core.

Unroll one dough sheet onto a floured work surface. Pulling on the sides of dough to straighten rounded edges, roll it into an approximate 12-inch square; cut dough into four 6-inch squares and brush the perimeter of each square with egg white. Set apple halves on each square. Bring up 4 corners of dough around apple and pinch edges to seal. Place in prepared baking dish. Brush dumpling tops and sides with egg white; sprinkle with white sugar. Repeat process with remaining apples and dough.

Bake dumplings in the preheated oven until pastry sets and turns golden brown, about 10 minutes. Reduce heat to 375 degrees F (190 degrees C) and bake until golden brown, about 20 minutes longer.

Meanwhile, bring 1 cup water, remaining 2 tablespoons butter, remaining 1/2 cup brown sugar, and remaining 1 teaspoon cinnamon to a boil in a small saucepan over medium heat. Dissolve cornstarch in 2 teaspoons water; whisk into hot syrup for a smooth sauce. Cover and keep warm.

To serve: Spoon a portion of warm sauce on a dessert plate; set apple dumpling on top and serve immediately.