Melt butter in a microwave safe bowl. While still hot, add sugar and mix until combined. Add ice cream and mix until smooth.
Add egg and vanilla extract, mix for just a few seconds, then add baking powder and salt. Mix until smooth, then mix in flour slowly. Mix dough just until it comes together.
Split the dough into 2 balls and place onto two separate cookie sheets covered with greaseproof paper. Cover with cling film and chill for at least 1 hour.
Preheat oven to 180°C/fan 160°C/gas mark 4
Press the cookies down with the palm of your hand otherwise they won't flatten totally.
Use a knife to mark the giant biscuit bases in to 6 wedges each. Like a pizza! Then go around the edge of the cookie with the back of a fork to press and make line patterns for hair!
Bake for about 20 minutes, until they start to get golden around the edges.
Cool at least 5 minutes on cookie sheets before moving to a rack to cool completely.
Use the red icing at the pointy end of each biscuit to make red noses. Make the icing using the icing sugar and water. Dunk in your chocolate buttons and stick them 2cm in from the edge at the other end to be eyes. Use the black writing icing tube to add dots to the white eyes, then let all the icing dry and go hard.