Add the marshmallows to a food processor and blend until powdery. It’s okay if a few larger pieces remain. Add the milk to a large bowl and pour in the blended marshmallows. Stir to combine, then let sit at room temperature for 30 minutes.
After 30 minutes, add the ice cream, marshmallow milk, vodka and vanilla extract to a blender. You can add extra cereal if you’d like! Blend until combined and pour into glasses. Top with frosting (or whipped cream!) and some extra marshmallows.
