Place blueberries in a medium saucepan and cook over medium heat until thickened and all berries have popped open, about 30 minutes. When you run a spatula across the bottom of the pan, it should leave a trail. Place the cooked blueberry jam in the fridge to completely cool. If it isn’t cold, it will leave lots of ice crystals in the ice cream and make it so the dessert doesn’t set properly.

In a large bowl, combine cream, sweetened condensed milk, and vanilla. Refrigerate until cool.

Once cooled, beat the cream mixture using a hand-held mixer or a stand mixer on medium-high until thickened and custard-like, about 5-10 minutes.

Spoon or pour the first layer of the ice cream mixture into a container or 2-quart dish, covering just the bottom of the dish. Dollop the blueberry jam over the top of the ice cream and swirl the jam into the cream. Continue layering and swirling like this, ending with ice cream at the top.

Tap the bottom of the dish on the counter a couple of times to help get any air bubbles out of the mixture. Cover and freeze several hours or overnight.

When ready to serve, let the ice cream sit on the counter for 5 to 10 minutes before scooping.