In a large mixing bowl, combine the all-purpose flour, salt, granulated sugar, and dry yeast. Cut in the cold butter until coarse crumbs form, then mix in the egg and add cold water gradually. Wrap the dough in plastic wrap and refrigerate for at least 1 hour.

Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper. Roll out the chilled dough into an oval shape, about ¼ inch thick. Spread the spiced apple filling evenly over the surface, fold the dough over, sealing the edges, and shape it into a loose oval on the baking sheet.

Brush the top of the kringle with whisked egg for a golden crust. Bake for 25 minutes or until golden brown and puffed up.

Let the kringle cool for about 10 minutes. Whisk together powdered sugar and a splash of milk to create the glaze, then drizzle it over the kringle.