In a large bowl, use an electric mixer to combine the sugar, cream cheese and egg yolks; beat at high speed until smooth.
In a medium saucepan, combine the milk and half-and-half; bring to a boil. Remove from heat.
Gradually add the hot milk mixture to the cheese mixture, a spoonful at a time (being careful to temper the mixture and not 'cook' the egg), stirring constantly with a whisk until all has been incorporated. Return the milk mixture to the pan. Cook over medium-low heat 5 minutes or until a thermometer registers 160°, stirring constantly. Scrape the mixture into a bowl and place it on top of ice in another bowl. Cool completely, stirring occasionally.
In a small saucepan, combine the blueberries, powdered sugar, and 1/4 cup water; bring to a boil. Reduce heat, and simmer for 10 minutes or until the mixture thickens slightly, stirring frequently. Remove from heat, and cool completely.
Stir the blueberry mixture into the milk mixture. Refrigerate several hours until mixture is very cold.
Pour the mixture into the freezer container of an ice-cream machine; process according to the manufacturer's instructions. Spoon the ice cream into a freezer-safe container; cover and freeze for 1 hour or until firm.
Sprinkle graham cracker crumbs on top of individual servings to complete the cheesecake theme!