In a medium saucepan, bring heavy cream, corn syrup, sugar, cocoa, salt 3 oz. chocolate chips to a boil over medium heat.

Stir until chocolate has melted.

Cook on low for 5 minutes.

Remove from heat, stir in the remaining 3 oz. chocolate chips, butter, and vanilla.

Stir until smooth.

Serve hot or pour into a canning jar and cool before placing the lid on top.

Refrigerate after it has cooled.

Heat before serving if you want a smooth pouring sauce or spread on at room temperature for a thick fudge like frosting or filling.