To form a crust, pat one package of crescent rolls into the bottom of an ungreased 13x9x2-inch baking pan or a 3-quart rectangular baking dish.
In a large bowl, beat the cream cheese, egg yolk, the 1 cup sugar, and vanilla with an electric mixer until well combined. Spread evenly onto crust.
On a lightly floured surface, roll out second package of rolls to form a 13x9-inch rectangle, pressing seams to seal. Place on top of cheese mixture.
For topping, in a small bowl, beat the egg white until foamy; spread over top crust. Stir together nuts and the 1/4 cup sugar. Sprinkle over top.
Bake in a 325 degree F oven for 30 to 35 minutes or until golden. Cool in pan on wire rack. Cover and chill until served. Makes 20 to 24 servings.