Mix powdered sugar and cocoa in a large microwave safe bowl. Cut butter stick into slices(do not use margarine because fudge will not set)and add to sugar/cocoa. Measure milk very accurately (this is a liquid sensitive recipe) and add vanilla to the milk. Pour milk/vanilla into bowl. Miccrowave on high for 1 minute. Add nuts, stir. (this will look like a mess and you just know it won't work) Microwave 1 more minute. Stir until all butter is melted and pour into a 6x8 pan or an 8x8. Let sit until firm. ENJOY!