Start by preheating your oven to 350°F (175°C). This is an important step that will set the stage for your fudge to come together perfectly.
In a medium saucepan, combine the stick of unsalted butter and the semisweet chocolate morsels over low heat. Stir frequently until both ingredients are melted and fully combined. Make sure not to let it boil; you want a smooth, glossy mixture, not a gritty mess.
Once the chocolate and butter mixture is melted, remove it from the heat. Let it sit for a minute before whisking in the two large eggs. You don’t want to cook the eggs, just integrate them into this delicious mixture.
Next, sift in the pound of icing sugar and the 1/4 cup of cocoa powder. Add the teaspoon of pure vanilla extract. Stir everything together until combined. This step will require some elbow grease, but the effort will pay off with the amazing texture you’re about to achieve.
Once everything is mixed well, pour the fudge batter into a greased 9x9-inch baking dish. Spread it evenly across the dish, making sure the top is smooth.
Place the baking dish in the preheated oven and bake for about 25 minutes. Keep an eye on it as every oven is a bit different. You want a fudgy center—no one likes dry fudge.
Once it’s done baking, remove the dish from the oven and let it cool completely. After cooling, slice it into squares. You can indulge right away or store it for later.