Pre-heat the oven to 350°.
Lightly coat an 8-inch square baking pan with non-stick spray.
In a small bowl, mix together graham cracker crumbs + butter with a fork until evenly moistened. Press evenly into the bottom of the prepared pan.
Gently beat cream cheese, sugar + vanilla extract until smooth using an electric mixer (or a stand mixer with the paddle attachment).
Gradually beat in Greek yogurt, egg whites, lemon juice, + flour. Do not over beat. When smooth, pour evenly over graham cracker crust.
Stir jam until smooth. Drop evenly-spaced small spoonfuls over the surface of filling.
Using a knife, swirl jam gently through filling to create a marbled effect.
Bake 25-30 minutes or until center is almost set. Cool to room temperature.
Chill a few hours in the refrigerator.