Cream butter and both sugars with electric mixer until creamy and smooth. Beat in egg and vanilla.
In separate bowl, whisk together flour, baking soda, cinnamon, cornstarch and salt. Add flour mixture to butter/sugar mixture, just until ingredients are combined. Stir in chow mein noodles. Cover with plastic wrap; refrigerate dough for at least 4 hours or overnight.
Preheat oven to 350 degrees F. Scoop 1½-inch balls of dough and drop onto parchment paper-lined baking sheet. Press a few pieces of candy corn into the top and center of each cookie, making sure the candy corn doesn't touch the baking sheet. Bake 8-10 minutes or just until set. Let cool on cookie sheet for 5-10 minutes before removing to wire racks to cool completely.