Melt chocolate: combine and melt both chocolates together in a microwave (see notes). Set aside.
Add everything except chocolate to a pot: place all ingredients except the melted chocolate into a small to medium sized pot that will be about halfway full once all the ingredients are added (adding the water first, and then the dry ingredients to prevent them from sticking to the bottom of the pan).
Dissolve sugar: cook mixture on medium heat, whisking slowly, but frequently until the sugar dissolves (this makes sure your sauce is nice and smooth when finished!).
Add chocolate: once your mixture is steaming, remove the pot from the heat momentarily and whisk in the melted chocolate until fully incorporated. Be sure to whisk while pouring the chocolate in to prevent the chocolate from burning on the bottom of the pot.
Simmer and cook: return the pot to medium heat, set a timer to start counting down 15 minutes, and stir continuously until the mixture begins to slowly bubble. Adjust your burner heat to maintain a slow simmer (but not full boil, which may require you to lower the heat slightly), stirring frequently to prevent burning.
Cool and store: at the end of the 15 minutes, remove fudge from heat. If possible, check your temp is at least 215°F on an instant-read thermometer (see notes). When ready, fudge will have thickened significantly, and be holding full lines of the whisk or spatula when you stir it.Let cool for 15 minutes in your pan, stirring occasionally to prevent a skin from forming on top.
Transfer and store: transfer cooked fudge to a heat-safe container (like a Pyrex or mason jar) and allow it to cool completely uncovered. Once at room temperature, cover or seal its container and store in the fridge until your nest sundae bar extravaganza. Fudge can be stored in the fridge for 2-3 weeks.
Reheat and enjoy: to reheat, simply transfer your desired amount of fudge into a microwave safe container and heat in 10 second intervals, stirring in between each, until a pourable texture is reached. Pile the chocolatey goodness on top of your favorite ice cream scoops and enjoy a match made in heaven!
Notes
Melting Chocolate: when melting chocolate in the microwave, use 50% power or less in 30 second intervals, stirring well between each interval to avoid burning the chocolate. If you don't have a microwave, place chocolate chips in a metal bowl that fits over the top of your sauce pot. Use your pot as a double boiler, and allow the bowl to remain there for 2-3 minutes until the chocolate is melted, stirring the chocolate occasionally to encourage even melting (and be careful to not get burned by the steam escaping from the pot/bowl seam!).
No thermometer? While a thermometer is certainly the best way to predict the final texture of your fudge, don't worry if you don't have one! If you follow the visual cues of a holding a slow bubbling simmer, simply time your cooking to 15 minutes as directed after you add the chocolate. Then remove your mixture from the heat when the timer goes off, and you should be good to go!
It’d mean so much to me if you could please give the recipe card a ⭐ rating on the site and leave a comment to help others find this sweet recipe! Xo, Jocelyn @ Mint+Mallow