Line a 9x9 inch dish with foil or sheets of parchment paper. You can use a larger dish like 9x13, the fudge will just be a bit thinner. Give the foil or paper a spritz of cooking spray or a swipe of melted butter to help it peel off later
Add all the ingredients except the vanilla extract into a medium heavy-bottomed pot and place on low heat stirring frequently.
Once the mixture has thickened and become shiny stir in the vanilla and pour into your prepared dish and smooth with a spatula. Set aside to cool completely, at least an hour.
When your fudge has cooled down remove from dish, peel foil or paper off and cut into squares with a sharp knife.
You can enjoy the fudge immediately or wrap in parchment or wax paper.
You really need to cook the fudge until it's thickened up and appears glossy. THat's when you know it's time to transfer to the dish to set.
Use semisweet, bittersweet or a combination of the two depending on personal taste.
Don't use high heat! The chocolate will burn and seize.
Try adding in a teaspoon of instant espresso to the pot to amp up the chocolate flavor.