Lightly grease a large dinner plate with butter and set aside.

In a heavy-bottomed saucepan, combine the sweetened condensed milk, cocoa powder, 1 tablespoon of butter, and salt off the heat. Stir to combine.

Place the pan over medium-low heat. Cook, stirring constantly and scraping the bottom and sides, until the mixture thickens significantly (about 10-15 minutes).

The fudge is ready when you run your spatula through the middle and it takes 2-3 seconds for the mixture to flow back together.

Pour the hot mixture onto the prepared greased plate. Spread slightly and let it cool completely at room temperature (1-2 hours).

Once cool, grease your hands with butter. Scoop about a tablespoon of the fudge, roll it into a ball, and flatten it into a small disc in your palm.

Place one gummy candy in the center of the disc. Fold the chocolate around the gummy, sealing it completely, and roll into a smooth ball.

Roll the stuffed ball in the chocolate sprinkles until fully coated. Place in a mini paper cup. Repeat with the remaining dough.