In a medium saucepan, combine the cocoa powder with 1/2 cup water and cook over low heat, stirring constantly, for 1 minute. Stir in the milk and sugar and bring to a simmer. Add the chocolate chips and vanilla and cook, stirring, until the chocolate is melted and the mixture is smooth, about 5 minutes.
Serve the fondue warm with the apricots, apples, pretzel rods and marshmallows for dipping.
The Do's and Don'ts of Cooking with Chocolate