In a mixing bowl, whisk milk, sugar and vanilla extract until sugar is dissolved.
Whisk in Greek yogurt, until smooth and fully incorporated.
Put freezer bowl in ice cream maker with paddle attachment. Turn ice cream maker on and pour yogurt mixture into bowl. Let ice cream maker churn mixture until frozen, about 20 minutes.
While ice cream maker is churning, crush chocolate sandwich cookies in a sealed sandwich bag. Can use the flat end of a meat tenderizer, the bottom of a glass, or a clean hammer to crush the cookies.
During last 5 minutes of churning, add in crushed cookies.
You can either enjoy the frozen yogurt immediately by serving in a bowl or ice cream cone, or you can freeze into popsicles. If you use popsicle molds, put the frozen yogurt in another bowl or measuring glass, and stir to soften slightly. Spoon and pour frozen yogurt into popsicle mold. Add popsicle sticks.
Freeze frozen yogurt in popsicle molds for several hours. This ensures that the popsicle stick will not separate from the frozen yogurt bar when removing from the mold.
After frozen yogurt bars are completely frozen, run under warm water until they can easily be removed from popsicle molds.
Enjoy!
