Crush graham crackers in a blender or food processor. If you don't have a blender handy, you can place the grahams in a ziploc bag and roll with a rolling pin or pound with a meat tenderizer. 2 packages of graham crackers make 2 cups.
In a small bowl, mix together graham crumbs and melted butter.
Firmly press graham mixture into tart pan, making sure to press up the sides as well.
Bake graham crust at 350° for 10 minutes, or until lightly browned. Set aside to cool.
In a medium-size bowl, blend yogurt and whipped topping until creamy and smooth.
Spread yogurt filling into tart pan.
Freeze yogurt tart for 2 hours.
When it's time to serve, allow 10-20 minutes thaw time depending on the ambient temperature.
Prep a baking sheet or cutting board with parchment paper. Carefully and gently lift tart away from the pan by pressing the bottom movable piece. An extra set of hands is helpful.
Place the tart on the parchment covered surface and decorate the tart with fresh blueberries and set aside graham crumbs.
Cut on the diagonal for extra pizzazz.
Keep leftovers in the refrigerator or refreeze.