Prepare the sauce. In a saucepan, combine pureed berries and sugar. Bring to a boil. Place butter and white chocolate in a tall vessel or glass. Pour berry mixture over it. Using an immersion blender, blend to combine.
Pour ½-1 inch of berry sauce into individual cups. Place in freezer to set for 30 minutes.
Meanwhile, prepare the cheese mixture. In a large bowl, combine Quark cheese, sour cream, and sugar.
In a saucepan, bring heavy cream and milk to a boil. Pour over cheese mixture. Using an immersion blender, blend until smooth. Add a layer of the cheese mixture over the berry mixture in each cup. Let set in the refrigerator for 1 hour
Once set, you can pipe additional cheese mixture on top as a garnish. These cups can be frozen for up to one month. Serve semi frozen or very cold.
Recipe by Between Carpools at https://betweencarpools.com/efrat-libfroind-easy-cheesecake-recipe/