In a large saucepan, stir together sugar and cocoa until all mixed together. Add Karo. Add milk, ½ cup at a time to help get every molecule of corn syrup from the measuring cup you just used for the Karo. Stir it all together until combined. Cook over med-high while stirring until it reaches firm-ball stage. The mixture will rise to near the top of the pot and then start settling down again before that happens. Start testing for firm ball when the drops at the edge of the spoon come together into one drop before falling off the spoon. A few drops in some faucet-cold water in a Pyrex measuring cup should come together into a ball that tries to hold its shape if you’re careful not to squish it. Remove from heat and put the butter into the pot but don’t stir it in. Wait until you can touch the bottom of the pot without burning yourself – usually between 30 minutes and 1 hour. Add the vanilla and stir to incorporate the butter and vanilla into the fudge before beating vigorously until your arm falls off. You can stop once the candy loses its gloss and is stiffening up. Stir in pecans quickly and pour the fudge into a pan. Scrape the pot and spoon with spoons to make popsicles you can eat until you’re sick. When the fudge is set up, cut it into cubes and try not to eat any of it because it’s for company.
Anything is possible because everything is impossible.