I buy Oppo too, or sometimes make ice cream lollies (it is possible to make softer ice cream without a machine but it is a lot of work). I use a pot of double cream, cocoa and erythritol sweetener as a quick cheat. Dissolve the cocoa and sweetener in a little warm cream, let it cool then whip the rest of the cream and fold in the cocoa mix. Separate into portions and freeze. I've also used strawberries mixed with sweetener and cream, covered with a little melted 85% chocolate.