Karens' Famous Fudge

I have to say, I have tried many fudge recipes over the years, but the best ever, is this one shared by a friend and ex co-worker, Karen (and thank you for letting me share it)!
It can be tricky, so make sure that you follow the directions exactly. And that you have a good mixer/beater (Karen once burnt one out)! Keep this recipe on hand for the holidays, as it makes a great gift!

The following is for a 9x13 pan.

Ingredients:
6 cups brown sugar
6 cups icing sugar
1 pound butter
1 can Carnation evaporated milk
1 teaspoon vanilla

Directions:
In a large saucepan over medium heat, melt butter. Add brown sugar and milk. Stirring, cook for 7-8 minutes.
Remove from heat. Add icing sugar a cup at a time while beating. Add vanilla. Continue beating for 5 minutes.
Pour in to pan. Refrigerate until set, and cut in to small squares.