1 (7 oz.) pkg. chocolate bits
1 tsp. vanilla
1 stick butter (must be butter)

Put these 3 things in bowl. In a heavy saucepan:

1 sm. can milk
10 lg. marshmallows
2 c. granulated sugar

Bring to boil stirring constantly boil 3 minutes. Pour over ingredients in the bowl and stir until chocolate is melted. Pour into buttered pan. Cut in squares when cool.