1tin condensed milk (397g) chilled preferable, but not essential
1tspvanilla bean paste
200gfull fat cream cheesesoftened at room temp
Melt the butter in a small saucepan.
Place the biscuits inside a sandwich bag and crush with a rolling pin until some are fine crumbs and some pieces are still 1 or 2 cm big (alternatively use a food processor or pestle and mortar).
Mix the biscuit crumbs with melted butter and a pinch of salt, then set aside.
In the same saucepan, with the biscuits and butter removed, add blueberries, sugar and the juice of half a lemon. (Before juicing, zest the lemon into a bowl big enough to whip the cream.)
Cook the blueberries until they break down and release their juices. This will take around 7 minutes. Mix cornflour with a few tablespoons of cold water and pour into blueberry mixture. Cook for one minute more to thicken.
Allow the blueberry mixture to cool in the fridge. Pouring onto a flat chilled surface (such as a chilled plate or baking tray) speeds up the process.
In the large bowl with the lemon zest, whip the double cream until thickened but not stiff peaks.
Mix the cream cheese inside it's container a little to loosen, then add to the cream along with the vanilla and whip until stiff peaks form.
Add the condensed milk and keep whipping until soft peaks form.
Gently ripple the cooled blueberries and biscuit crumbs into the ice cream, reserving some crumbs to scatter on top. Then pour into a 9x5” loaf pan or similar sized container and sprinkle with some more of the biscuit crumbs.