Black raspberry ice cream is an unforgettably delicious frozen treat thanks to the unique flavor of these elusive berries. If you can't get your hands on black raspberries, use what you have, but don't miss out on this summertime classic.
In a small saucepan, cook the berries and sugar over medium heat for a few minutes until the fruit is broken down and the berries have released their juices.
Dissolve the cornstarch in a little bit of water (1-2 Tbsp), and stir into the berry mixture. Cook for 1-2 more minutes until bubbling throughout and thickened slightly.
Push the berry compote through a fine mesh sieve to remove the seeds, and set aside to cool completely, and then chill until needed.
For the ice cream
Whisk the egg yolks in a small bowl until smooth, and set aside.
Pour one cup of the heavy cream into the bowl you plan to chill the ice cream mixture in, and set a strainer over it.
Combine the rest of the heavy cream, milk, salt, and sugar in a small saucepan and heat over medium heat until steaming and just starting to bubble around the edges, stirring occasionally.
Pour a little bit of the hot milk mixture over the egg yolks, whisking it in while you pour. Then pour the egg mixture back into the saucepan and return to the heat.
Whisking constantly, continue to heat the custard until it thickens. Don't allow it to boil. It will not get super thick like a pudding, but more like a thin pancake batter.
Once thickened, pour the custard through the strainer you set over the heavy cream.
Add the vanilla extract and stir everything together. Chill in the fridge at least 6 hours or overnight.
Churn the ice cream in your ice cream making according to the manufacturer's instructions. In the very last minute or two of churning, add a tablespoon or two of your black raspberry compote and allow it to get swirled into the vanilla ice cream a bit.
Put about half of the ice cream mixture into a freezer container, top with about half of your berry compote, and swirl it in using a chopstick, or a butter knife. Top with the remaining ice cream, and swirl in the rest of your berry mixture on top.
Freeze for a few hours until it becomes scoop-able, and enjoy!