To prepare the ice cream base:

1. Combine the milk and 2 tablespoons of the sugar in a medium saucepan over low heat. Bring to a simmer, stirring occasionally. In the meantime, combine the egg yolks and the remaining sugar in a bowl and whip with a hand mixer on medium speed until fluffy, about 3 minutes. Once the milk mixture has come to a simmer, carefully add 1 cup of the warm milk into the egg mixture in a slow and steady stream, whisking all the while, over the course of 30 seconds. Don’t add it all at once or you’ll risk scrambling the eggs. Once the milk has been added, pour the mixture back into the saucepan with the remaining milk and cook over medium-low heat while stirring constantly until the mixture barely thickens enough to coat the back of a spoon (about 4-5 minutes). Don’t let the mixture boil. Pull the saucepan off the heat and whisk in the mascarpone and salt until incorporated.
2. Strain the custard into a gallon-sized plastic bag and seal it. Place the bag in a sink filled with ice and cold water to help the mixture chill quickly. Alternatively, you can strain the mixture in a bowl and allow it to chill more slowly in the fridge. Once the mixture has chilled, process the ice cream in an ice cream maker according to manufacturer’s instructions, usually about 20 minutes. Once prepared, spread the custard into a loaf pan alternating with drizzles of the blueberries and crumbled cookies. I like to do three separate layers of custard and top each with a hefty amount of blueberry sauce and cookie crumbles. Swirl gently with a knife and then allow to freeze completely in the freezer. Enjoy!

To prepare the filling:

1. Combine the blueberries and sugar in a small saucepan over medium heat. Bring to a boil, reduce the heat, and simmer until the sauce has thickened slightly. Remove from heat to cool completely prior to use.