Heat the milk, sugar and salt in a medium saucepan on medium heat until sugar is dissolved and mixture has bubbles that appear around the edges. Do not boil.

Whisk the egg yolks together in a large bowl. While continuing to whisk, slowly add the hot milk mixture in a slow steady stream until it is all incorporated.

Pour the mixture back into the saucepan and set over medium high heat. Cook mixture, stirring frequently, until thickened and coats the back of a spoon, about 4-5 minutes. Remove from heat and pass through a mesh strainer if desired, to remove any lumps. Stir in heavy whipping cream and vanilla extract and chill completely in the fridge, at least 4 hours.

In a medium saucepan add the blueberries, sugar, lemon zest, cinnamon, and salt and set over medium heat. Cook, stirring frequently until berries are softened and juices have thickened and reduced, about 35-45 minutes. Let cool completely.

You can use either a food processor or a large ziplock bag and rolling pin to crush the graham crackers into the crumbs. Stir in butter and flour.

Bake at 350°F for 10 minutes, until golden brown. Let cool completely.

Churn chilled vanilla ice cream base in an ice cream machine according to manufacturer's instructions.

In a quart sized tupperware or bowl, alternated layering the churned ice cream, blueberry swirl and graham cracker crunch. Cover and freeze until firm, 2-3 hours.