Gather all ingredients

To make the pastry: Place flour and salt in a food processor and pulse to combine. Add butter and pulse until pieces are pea-sized.

Add sour cream and pulse to form a sticky dough. Cover dough tightly with plastic wrap and refrigerate for 8 hours, or overnight.

Preheat the oven to 375 degrees F (190 degrees C). Line a large baking sheet with parchment paper.

To make the filling: Place egg yolk in a medium bowl; set egg white aside for egg wash.

Add cream cheese, brown sugar, and cinnamon; beat with an electric mixer until smooth. Stir in 1 cup toasted walnuts until well combined.

Divide chilled dough in half. Roll each piece of dough into a 10x12-inch rectangle on a lightly floured surface.

Working from a short side, spoon 1/2 of the filling along the center four inches of each rectangle. On both sides of the filling, cut the unfilled pastry into eight horizontal strips. Working top to bottom, fold each strip over the filling, alternating sides. Press to seal ends and tuck under; arrange braids on the prepared baking sheet.

Beat egg white and 1 tablespoon water together until smooth; brush evenly over each braid.

Bake kringles in the preheated oven until golden brown, about 30 to 35 minutes. Cool on the baking sheet for 30 minutes.

While pastries are cooling, make glaze: Mix together confectioners' sugar and 2 tablespoons water in a small bowl until smooth and thin enough to drizzle.