Ooh....that sounds good...and, easy!
1 lb powdered (confectioner) sugar
1/2 cup cocoa
Mix together well in micro safe bowl - fork or whisk
Make small indent in middle and place 1/2 cup butter (one tube) in center
Pour 1/4 cup milk over butter.
Micro 2 mins
Add 2 tsp vanilla
Mix
Add nuts if desired
Pour into buttered dish. Freeze 20 mins. Cut and enjoy