Preheat oven to 350 degrees F. Cream butter and 3 1/2 ounces sugar, then add pinch of salt, vanilla and 2 cups potato chips and mix until combined. Wrap dough in plastic wrap and refrigerate until firm (about 1 hour).
Scoop dough into desired size and roll into a ball. Place on a parchment paper-lined sheet pan, leaving a 2-inch space between each cookie. Press thumb in center of ball, creating a thumbprint. Bake until cookies are golden brown (about 8 to 10 minutes). Reserve to cool.
To make caramel, pour 6 ounces sugar, corn syrup and 1 tsp salt in a heavy-duty saucepot and cook until medium amber in color. Meanwhile, heat cream to warm. When sugar is medium amber in color, return to a boil before mixing in remaining sugar. Add warm cream in small batches, reducing after each addition. Remove pot from heat and reserve to cool before adding to cookies.
To assemble, put a dollop of caramel in center of each cookie. Refrigerate to cool and set caramel. Sprinkle remainder of crushed chips on top of caramel, and dust lightly with powdered sugar.