- Bundle smashed juniper berries, cardamom, and cinnamon in cheesecloth with a small tie to make a sachet.
- In a small, heavy-bottomed pot, add sugar and enough water to make the mixture look like wet sand. Turn heat to medium high and cook sugar until it becomes caramel in color. Add blueberries and spice sachet, and cook for 10 minutes, until blueberries break down. Mix cornstarch with 2 tablespoons of water to create a slurry and add to blueberry mixture. Boil until very thick, about three minutes. Stir in lemon zest and juice, and then cool in refrigerator.
- In the bowl of a stand mixer fitted with whisk attachment, combine condensed milk, cream, and salt and mix on high until mixture forms stiff peaks. Gently fold in blueberry mixture. Pour into a loaf pan and freeze for 6 hours.