Make the cookie dough: Spread the flour out on a baking tray, and bake for 5 minutes to any kill bacteria.
In a large bowl, cream the butter and sugars. Add the vanilla and chocolate chips, and mix until thoroughly incorporated. Add the baked flour and mix well, then remove ¼ of the mixture and set aside. Add the egg yolk to the rest of the mixture and mix well. Use this mix to line 24 holes of the mini muffin tin, shaping them up the sides. Pop in the freezer for 20 minutes to firm up, then bake for 15 minutes. Press the cups back into shape while hot if they have sunk a little, then leave to cool.
Roll the remaining egg-free cookie dough into tiny little balls.
Make the ice cream:
Whip the double cream to soft peaks, then add the condensed milk and cookie dough balls. Stir everything together well. Pour into a small dish and freeze for a minimum of 4 hours.
To serve: Dip each cooled cookie dough cup into the melted chocolate then place upright on a cooling rack to set. Using a melon baller, scoop rounds of the ice cream and fill each cup. Serve right away.
