In a medium bowl whisk together whole milk, chocolate liqueur, and peanut butter whiskey.
Slowly pour chocolate instant pudding into the bowl of liquids while hand whisking. Continue to mix until well combined and no lumps remain. Allow pudding to set at room temperature for 5 minutes.
Gently fold Cool Whip into the pudding until no white streaks remain.
Portion into two ounce shot glasses. Place in the freezer for 40-50 minutes to further thicken and set up. Garnish with whipped dairy topping and a halved chocolate peanut butter cup. Serve immediately.
