In a pan set over a medium heat, add the blueberries, sugar and lemon juice.
Leave them to simmer for 3-4 minutes stirring occasionally, and use a wooden spoon to crush the blueberries lightly.
Once you have the texture of a lumpy sauce, remove the pan from the heat and leave it to cool down completely.
Meanwhile, add the cream to a large mixing bowl.
Use a hand mixer to beat the cream until you get soft peaks, then add the condensed milk and cream cheese, and beat again.
Add the biscuits to a ziploc bag, and use a rolling pin to crush them roughly.
Transfer the biscuits to a bowl, add the melted butter, and mix them well.
Add the cream mixture to a metal loaf tin, and top it with the blueberry sauce.
Use a spoon to swirl the sauce around, then top with the crushed biscuits.
Cover the tin with kitchen foil, and freeze it for at least 6 hours, ideally overnight.
If the ice cream is to frozen to scoop out, just leave the tin at room temperature for 30 minutes or until it has the desired consistency.