Heat sweetened condensed milk. Pour the condensed milk into a pot and bring it to medium heat. You want it to turn from thick, to runny and pourable. When it starts to bubble around the edges, it's done! Transfer the warmed condensed milk into a bowl.
Stir in the cocoa and other flavors. For maximum silky, smooth tootsie rolls, sift the cocoa powder into the bowl. Then choose your flavor adventure. Vanilla, peanut butter, matcha, strawberry...even fancier, chestnut or red wine. Try to use powdered forms of these flavors so they blend evenly into the tootsie roll mixture. Any extra moisture or chunks will make it difficult to roll.
Chill the Tootsie Roll mixture. This stuff is sticky. So, place it on a piece of plastic wrap and wrap it up. Chill it in the fridge for 3 hours or overnight. If you're impatient, 1 hour will do.
Roll into a log, then cut. Use a knife to divide the mixture into forths. Take one piece and start rolling it on a clean work surface. Continue rolling it into a long, skinny log, about 1/4-inch in diameter (or the size of Tootsie Roll, doi). Cut the log into 2-inch pieces for the classic size. You can go longer if you like.
Wrap in wax paper. This step can be wonderfully tedious if you like this kinda stuff. Otherwise, get a friend to help. To wrap each Tootsie Roll, cut a 3-inch squash of wax or parchment paper. Place the Tootsie Roll at the center of the square. Wrap the bottom piece of paper over the Tootsie Roll until it overlaps with the top piece. Twist the ends a couple times and repeat with the remaining candies.