In a large mixing bowl, combine all-purpose flour, sugar, salt, and active dry yeast. Cut in cold butter until coarse crumbs form. Gradually mix in the milk and egg until a dough forms. Cover and refrigerate for 30 minutes.

While the dough chills, peel and slice the apples. In a separate bowl, mix apple slices with sugar, cinnamon, and nutmeg until coated.

On a floured surface, roll out the chilled dough into an oval, about ¼-inch thick. Place the apple filling in the center, fold over the sides to create a horseshoe, sealing edges tightly.

Preheat oven to 375°F (190°C). Transfer the kringle to a parchment-lined baking sheet, brush with an egg wash, and bake for about 25 minutes until golden brown and bubbling.

Allow kringle to cool for 10 minutes. Mix powdered sugar with vanilla and milk to form a glaze, then drizzle over the warm kringle.