Cook the peeled potatoes in boiling water until tender, about 15 minutes. Mash thoroughly until smooth and let cool completely.

In a large bowl, combine the mashed potatoes with softened butter and vanilla extract. Beat with a mixer until smooth and creamy.

Gradually sift in the powdered sugar while beating continuously until the mixture is thick, stiff, and dough-like.

Optional: Mix in shredded coconut, chopped nuts, or chocolate chips for added flavor and texture.

Turn the dough onto a dusted surface with powdered sugar. Roll into a sheet about 1/4 inch thick.

Cut into desired shapes using a cookie cutter or knife. Place on parchment-lined tray.

Refrigerate for at least 1 hour to firm up.

Serve at room temperature or chilled. Store in an airtight container for up to 1 week.