Heat oven to 350°F. Line 15x10-inch pan with sides with parchment paper.
In medium bowl, beat cream cheese, sugar, peanut butter, vanilla and egg yolk with electric mixer on medium speed 1 minute or until fluffy, scraping sides of bowl if necessary; set aside.
Arrange biscuits in 2 rows of 4 biscuits in center of pan, with sides of biscuits just touching. Press or roll biscuits to 14x9-inch rectangle. Spread cream cheese mixture over dough to within 1/2 inch of edges. Using parchment paper, bring long sides of dough over filling, overlapping slightly in center. With fork, lightly beat egg white; brush over top and sides of dough.
Bake 25 to 35 minutes or until golden brown. Cool 10 minutes. Spoon and spread jam down center of pastry. Carefully remove to serving plate. Serve warm.