Take a couple handfuls of pretzels and throw them in a ziplock bag. Using a rolling pin, give the pretzels a couple taps. You can also roll across the pretzels a few times until you get the size pretzels you want.
Measure out the pretzels, oats, and peanut butter. It's best to have these ready for when the mixture is done. Also, lay down a strip of wax or parchment paper.
In a large saucepan, add the butter, sugar, milk, and cocoa powder. Put the heat on medium and stir until everything is a liquid consistency. Continue stirring until the mixture comes to a boil.
When the mixture starts to boil, set the timer for 2 minutes. Stir occasionally.
When the timer goes off, dump in the pretzel, oats, peanut butter, and vanilla. Stir until everything is combined. You'll want to do this quickly since the mixture will start hardening.
Take a large cookie scoop, and start scooping the mixture onto the wax paper. It will take 10 to 15 minutes for the no-bakes to harden completely. They should pull right off the wax paper when they are dry.