Peanut Butter Cup Hot Chocolate

1  cup  hot chocolate mix
8  cups  hot water
3/4  cup  chocolate syrup
1/4  cup  peanut butter
1 1/2 tsp vanilla

Combine the hot chocolate mix and the water in a slow cooker. 
Stir in the chocolate syrup.
Cover and cook on low for 2 hours.
Whisk in the peanut butter and vanilla, until smooth.
Ladle into a mug to serve.