Gather ingredients: Gather all ingredients. Chop nuts if using.
Mix dry ingredients: Combine sugar and cocoa in a medium saucepan. Stir until well combined.
Add wet ingredients: Add butter and evaporated milk to the saucepan. Stir over medium heat until butter melts and the mixture is smooth.
Cook fudge: Continue cooking over medium heat, stirring constantly, until the mixture reaches the soft ball stage (234-240°F). This may take 10-15 minutes.
Add vanilla and nuts: Remove from heat. Stir in vanilla extract and chopped nuts (if using).
Pour and cool: Pour the hot fudge mixture into a greased 8×8-inch baking dish. Let cool completely at room temperature, then refrigerate until set (about 2 hours).
Cut and serve: Cut fudge into squares and enjoy!
