Using a 5×9 pan (typically the same size as a banana bread pan – but if you want thinner pieces, use 8×8) line pan with wax parchment paper or wax paper. Make sure you have some extra hanging over on all four sides.

Combine sugar, cocoa, buttermilk, sweetened condensed milk, and food coloring in a non stick pan. (I used a big pot). Stir to combine. Bring the mixture to a boil, stirring constantly, but do not scrape down the sides (this should help you avoid getting crystallized sugar in the fudge).

Using a well calibrated thermometer, make sure the fudge gets up to 238 degrees. Once it reaches 238 degrees, reduce heat and allow fudge to simmer. DO NOT STIR at this point. At all. Like seriously don’t even touch the pan. Allow fudge to cool down to 110 degrees and then add butter and vanilla.

Beat by hand or use electric mixer until fudge loses its sheen. (I used an electric mixer for 20 minutes. Not kidding. Some folks say this stage takes 3-5 minutes.)

Place the mixture in prepared pan and allow to cool, usually 1-2 hours.

This recipe yielded 25 small squares.