Classic Fudge

Combine the cocoa powder, sugar, and salt in a medium-sized saucepan. Stir until they are fully incorporated. Next, add the corn syrup and milk to the mixture, blending it thoroughly. Now, incorporate the butter into the mixture by stirring until it's fully incorporated. Heat the saucepan over medium heat, aiming for a temperature range of 235 to 240 degrees F (112 to 116 degrees C).

To check if the mixture is ready, drop a small amount of it into cold water. Observe how it behaves - when removed from the water and placed on a flat surface, it should form a soft ball that flattens slightly. Continue stirring the mixture occasionally to prevent scorching.

Once the desired consistency is achieved, remove the saucepan from the heat source. Use a wooden spoon to beat the mixture until it thickens and loses its shiny appearance. Finally, add the vanilla extract to the mixture and pour it into a buttered 9x9-inch baking dish. Allow the mixture to cool until it sets, then cut it into small squares for serving.