Preheat oven to 350°F.
In a large mixing bowl, beat the shortening and brown sugar until creamy.
Add the flour and oats, beating until well-blended.
Press into the bottom of a lightly greased 9x13 baking pan.
Bake for 15-18 minutes, or until pale golden brown at the edges.
Meanwhile, prepare cheesecake.
In a large mixing bowl, combine cream cheese and sugar, beating until smooth.
Add the peanut butter, beating until smooth and blended.
Add the eggs, one at a time, beating well after each addition.
Add the vanilla.
Spread the cheesecake filling evenly over the crust.
Drop the jam onto the cheesecake layer by large spoonfuls.
Swirl gently with a knife.
Bake an additional 30-35 minutes, or until cheesecake appears set when the pan is jiggled.
Remove pan to a wire rack to cool completely. Cut into bars. EAT!!