Pastry:
1/2 cup cold unsalted butter
1/2 cup sour cream (not low fat)
4 ounces cream cheese (not low fat)
1 1/2 cups flour

Filling:
1/4 cup unsalted butter, melted
1/3 cup sugar
2 teaspoons ground cinnamon
2/3 cup finely chopped walnuts

Egg wash:
1 large egg, beaten
1 tablespoon water

Pastry: Using a mixer or food processor, process butter until creamed. Add cream cheese and sour cream; blend well. Add flour. Mix until it just forms a soft ball. Divide into two balls, cover in plastic wrap and refrigerate at least 3 hours or overnight.

Preheat oven to 350 degrees. Lightly butter a cookie sheet or line with parchment paper.

Filling: Mix sugar and cinnamon in small bowl. Set aside.

Egg wash: Mix egg and water.

Assembly: Flour work surface and place balls, one at a time, on the surface. Roll out with floured rolling pin into two circles about 10 to 12 inches in diameter and 1/8 to 1/4 -inch thick. Brush each circle with half the melted butter. Sprinkle each with 1/4 of the cinnamon sugar and half the walnuts.

Using sharp knife or pizza cutter, cut each circle like a pie into 12 to 16 wedges. Beginning at the wide end, roll up each wedge to form a crescent. Place on cookie sheet.

Brush tops with egg wash. Sprinkle with remaining cinnamon sugar. Bake until golden brown, about 30 minutes.