Line an 8×8-inch baking pan with parchment paper or lightly grease it. Leave a bit of parchment hanging over the sides to make it easier to lift the fudge out later.
In a medium, heavy-bottomed saucepan, combine the chocolate chips, peanut butter, and sweetened condensed milk.
Set the pan over low heat. Stir slowly and steadily with a wooden spoon or heatproof spatula, scraping the bottom and sides often so nothing scorches.
Continue cooking and stirring until the chocolate chips are completely melted and the mixture is smooth, thick, and glossy. This usually takes 5–8 minutes. Do not let it boil.
Once everything is melted and well combined, remove the pan from the heat. Give it a final good stir to be sure the mixture is uniform.
Pour the warm fudge mixture into the prepared pan. Use your spatula to spread it into an even layer, smoothing the top as best you can.
Let the fudge cool at room temperature until it is no longer warm to the touch, then transfer the pan to the refrigerator. Chill for at least 2 hours, or until firm enough to cut cleanly.
Once firm, lift the fudge out of the pan using the parchment paper overhang. Place it on a cutting board and use a sharp knife to cut it into small squares.
Store the fudge in an airtight container, with parchment or wax paper between layers to prevent sticking. Keep it in the refrigerator for firmer fudge, or at cool room temperature if your kitchen isn’t too warm.
Variations & Tips
