In a large bowl, whisk together the flour and fine salt. Introduce the cold butter, kneading gently until the mixture resembles coarse crumbs with pea-sized pieces of butter.

Gradually incorporate the ice water until the dough coalesces into a smooth mass. Shape into a rectangle, wrap tightly, and refrigerate for at least 2 hours or overnight.

Toast the almonds in a warm oven at 350°F for 8-10 minutes until golden. Allow to cool, then grind finely in a food processor.

In a saucepan, combine the ground almonds, granulated sugar, heavy cream, thickening flour, almond extract, vanilla extract, and a pinch of salt. Stir over medium heat until the mixture thickens (about 5-7 minutes). Let cool completely.

Preheat the oven to 375°F and line a baking sheet with parchment paper.

Divide the chilled dough in half, rolling each piece into a 12x18-inch rectangle. Spread half of the filling onto each rectangle, leaving a ½-inch border, and roll jelly-roll style into a horseshoe shape.

Place on the prepared baking sheet and let rest.

Bake for 25-35 minutes until golden brown and an internal temperature of 200-210°F is reached. Allow to cool on the sheet for 10-15 minutes before transferring to a wire rack.

Whisk the sifted powdered sugar with milk and almond extract until smooth. Drizzle over cooled kringles and add slivered almonds as a garnish. Allow glaze to set for 15-20 minutes.