Melt the butter, milk, and sugar very slowly over the stove. Stir constantly because it will scorch easily.
In a large bowl combine the chocolate chips and vanilla. Add this mixture to the butter, milk, and sugar and stirring constantly until chocolate pieces have melted. Remove from stove. Grease your 8-inch by 8-inch square pan and spread the mixture evenly. Chill until firm and cut into bite-size pieces.
I found this in our old family recipe cookbook so I had to share it! I remember my grandmother's fudge was fabulous!