Blend the Base: In a blender, combine 4 cups of chocolate ice cream, 1 1/4 cups of milk, and 1/4 cup of creamy peanut butter. Blend until the mixture is smooth and creamy.
Prepare the Glasses: Using a knife, spread chocolate frosting around the outside of your serving glasses, keeping it about 2-3 inches from the top.
Add the Crunch: While the frosting is still wet, press 8 coarsely chopped peanut butter Oreo cookies, a handful of mini peanut butter cups, and chopped peanuts against the frosting on each glass.
Drizzle with Chocolate: Drizzle chocolate syrup down the insides of the glasses, creating a decorative effect.
Pour the Shake: Carefully pour the blended milkshake into the prepared glasses, being cautious not to disturb the toppings.
Top it Off: Generously add whipped cream on top. Feel free to stack it high!
Garnish Creatively: If you desire, use a straw to skewer optional cupcakes and place them on top of the whipped cream. Finish by sprinkling additional chopped peanuts, more cookies, and another drizzle of chocolate syrup on top.
Serve Immediately: Present the shakes while they’re cold and enjoy every last drop of your epic chocolate peanut butter milkshake!