In a medium bowl, whisk together egg yolks, brown sugar, and sugar until light and fluffy. Set aside.
Add cream, milk, vanilla, and salt to a pot. Place over medium heat, stirring frequently, until warm and beginning to steam.
Slowly pour some of the warm milk mixture into the egg yolk mixture, while whisking constantly to temper the egg yolks. Continue until all of the milk has been added.
Pour the mixture back into the pot and cook over medium heat, stirring constantly. Cook until the mixture thickens and coats the back of a spoon.
Pour the mixture into a heat-safe container. Cover and let cool slightly at room temperature for 20 minutes. Then, place in the fridge and chill overnight, or until completely cold.
Prepare the Blueberry Compote
Add blueberries, sugar, and lemon juice to a pot over medium heat. Cook until the berries start to release their juices, then blend until smooth.
Transfer the mixture back to the pot and bring to a simmer. Cook, stirring frequently, until most of the liquid has evaporated and the compote has thickened to a gel-like consistency that coats the back of a spatula well.
Transfer to a heat-safe container, let it cool slightly, then place in the fridge to cool completely.
Prepare Streusel Topping
Preheat oven to 350℉.
In a bowl, mix together melted butter, sugar, brown sugar, cinnamon, and salt until combined.
Mix in flour until combined.
Crumble into a pie plate or an 8 x 8 baking dish. Bake for 12-15 minutes until golden brown.
Allow to cool completely. Break into small crumbles.
Churn and Assemble the Ice Cream:
Churn ice cream according to manufacturer's instructions until it reaches a soft-serve consistency (about 20 minutes).
Add a thin layer of ice cream to a freezer-safe container, spread some blueberry compote on top, followed by some streusel topping. Repeat until all ingredients are used.
Freeze for 2-4 hours until firm and scoopable.
Notes
Prepare Your Ice Cream Machine - If your ice cream machine has a bowl that needs to be frozen, remember to freeze it in advance so it's ready when you need it. I like to freeze it for at least 24 hours to ensure it's fully frozen before using.Tempering the Egg Yolks - This step is important because it allows the eggs to heat up slowly, so they don't curdle and cause little egg lumps in your ice cream mixture.Cooking the Ice Cream - When cooking the ice cream, you'll know it's done when it coats the back of a spoon. If you want to use a thermometer, it should reach this point around 170℉.Strainer - Pouring the cooked ice cream base through a strainer or fine-mesh sieve is optional, but it ensures that you don't end up with any lumps or pieces of cooked egg yolk in your mixture if they weren't tempered properly.Chilling the Mixture - I prefer to chill the ice cream base overnight to ensure it's fully cold and allow everything to meld together. If you don't want to wait that long to churn your ice cream, you can move on to the churning step once the ice cream base is fully cold.Serving - If the ice cream has been in the freezer for an extended period of time, you may want to let it sit out on the counter for a few minutes to allow it to soften slightly before scooping.