These are technically called Duchess Potatoes, but the husband saw them and said, “Mashed Pototo Cookies!”, so that’s what they are in our house. They are a little different from the recipes I’ve seen for Duchess Pototoes in that I didn’t add egg yolk or do an egg wash or brush with butter.
Preheat oven to 350 and grease a cookie sheet.
Fill a pastry bag or plastic bag with mashed potatoes and pipe into mounds on the cookie sheet.
Bake until golden brown and crispy on the outside, it was about 40 minutes for me.