To make the Peeps vodka, place 4 yellow Peeps marshmallows into a large, sterilized mason jar and pour the ¾ cup of vodka over them.
Screw on the lid and shake together.
Leave for 24-48 hours, shaking occasionally.
Strain the Peeps vodka through a paper coffee filter or cheesecloth to remove the leftover candy and store the liquor in a clean, sterilized jar or bottle until ready to use.
If you want to add a sugar rim to your glasses, rub the lime wedge around the rim of the glasses and dip them into a saucer filled with sugar sprinkles. Set them aside.
To make the cocktail, pour the Peeps vodka, limoncello, and sweet and sour mix into a glass pitcher with ice. Stir to combine.
Pour into 4 martini glasses and decorate with a yellow bunny Peep marshmallow.