1. Chill the bowl you’re using to whip your cream and the beaters for 20 minutes.
2. Line the bottom of a 9″x5″ loaf pan with parchment.
3. While the bowl is freezing, make the streusel.

Make the streusel:

• Preheat the oven to 350 F (180 C).
• In a small bowl, mix the flour, brown sugar and cinnamon together until the sugar is evenly distributed in the flour.
• Pour in the melted butter, then use a fork to toss the ingredients together. Stir everything together until the crumbs start to form.
• Cover the bowl, and freeze for 10 minutes. Use a fork to scrape the bowl and break up the streusel into pea sized chunks.
• Scatter the cold streusel on a sheet tray and bake until the streusel is lightly brown and crunchy, about 8-10 minutes.
• Set it aside to cool while you beat the cream.

Finish the ice cream:

• Beat the cream and vanilla in the chilled bowl until you get stiff peaks.
• Open up the can of sweetened condensed milk, then drizzle it down the side of the bowl.
• Use a baking spatula to scrape out all the sweetened condensed milk, then fold the cream and milk together into a smooth, consistent mixture.
• Stir the jam in a small bowl to loosen up the texture.
• Sprinkle the streusel over the top of the cream.
• Scoop out dollops of jam all over the top of the cream, leaving a little jam left in your bowl for later.
• Fold the jam, streusel and cream together with about 6-8 lazy strokes of a baking spatula. The goal is to mix the jam in roughly so that you still can find streaks of jam.
• Smooth the ice cream into the pan, then spoon dollops of the rest of the jam over the top.
• Use a butter knife to make curvy zigzags as you drag it through the jam dollops. This will swirl the jam in and make the top look a little nicer.
• Cover the ice cream with plastic wrap.

Freeze:

• Freeze for 2 hours. After 2 hours, the ice cream will be partially frozen, but definitely not solid.
• Uncover the ice cream, then scatter the fresh blackberries over the top of the pan. Press the berries into the ice cream, pressing some of them down deeply, and others less so. When you’re done, the berries should be distributed throughout the ice cream.
• Cover the ice cream again and freeze overnight, or for at least another 6 hours.
• After freezing, if you like, you can transfer the ice cream to a lidded freezer container like a Pyrex of a Tovolo tub.