Berry Parfait

Directions

1. 1
   Whisk milk, juice and zest of 2 lemons, sugar and cornstarch in a pot over medium heat until mixture thickens, 3 to 4 minutes.
2. 2
   Let cool 2 minutes.
3. 3
   Whisk in yogurt.
4. 4
   Cook blue-berries, juice and zest of remaining lemon and sugar in another pot over medium heat, mashing until a chunky sauce forms, 2 to 3 minutes.
5. 5
   Divide graham cracker crumbs and sauce among 4 glasses; top each with 1/2 cup yogurt pudding.
6. 6
   Chill 1 hour.