In a small saucepan, combine chocolate chips, sweetened condensed milk, and peanut butter.

Cook over medium-low heat, stirring occasionally, until melted; about 2 minutes.

Remove from heat and stir in vanilla.

Stir in 2-tablespoons of boiled water at a time to thin it out; stir in more water to achieve desired consistency.

Pour over ice cream and serve.

To Store

Let cool completely.

Store in a jar and refrigerate.