In a large bowl, use an electric mixer to cream the butter at medium speed (for 2 minutes). Mix in the sugar and vanilla. Then mix in the egg. Then mix in the flour. Stir in 1 cup of the crushed potato chips. Cover the bowl and chill for 2 hours.
Preheat to the oven to 350℉. Line a baking sheet with parchment paper.
Roll the dough into 1-inch balls. Place them 2-inches apart on the prepared baking sheet. Dip the bottom of a glass in water, then in sugar and flatten each ball slightly. Sprinkle more crushed potato chips on top.
Bake for 10 to 12 minutes, or until the cookies have browned on the edges. Let cool on the baking sheet for a few minutes before transferring them to a rack to cool completely.