Hot Fudge Sauce

From Candymaking by Ruth Kendrick and Pauline H. Atkinson, used with permission

Ingredients:

(12 oz.) can evaporated milk (you could probably use half and half)
1/2 cup butter (if using unsalted, add a pinch of salt)
4 oz. of 70 percent Millcreek or Amana chocolate
2 cups sugar
1 tsp. vanilla

In a heavy saucepan, combine butter and chocolate and warm over low heat, stirring constantly. When melted, stir in sugar and milk. Bring to a boil, stirring, and cook until slightly thickened. Remove from heat and stir in vanilla. Cook slightly before using over ice cream. Store in refrigerator for several weeks. Can be warmed in microwave or served cold.