Allow the puff pastry squares to soften in the refrigerator. (It’s important to keep the dough cold so it doesn’t become sticky and difficult to work with.)

Peel and cut the potatoes into eighths.

Place in a small saucepan and cover with water.

Bring to a boil over medium-high heat, and let boil for 20 minutes until potatoes are totally soft.

Drain and mash.

While the potatoes are cooking, place the onion and oil in a small frying pan.

Sauté over medium heat for 20 minutes, stirring occasionally.

Raise the heat during the last five minutes to allow the onions to turn golden.

Add sautéed onions, mayonnaise, salt, and onion powder to mashed potatoes and mix well.

Prepare two puff pastry squares on a sheet of Gefen Parchment Paper or plastic.

Place one teaspoon potato mixture along the edge of a puff pastry square.

Roll up tightly and pinch ends closed.

Slowly stretch the roll in your hands until about doubled in length.

Place on counter and slowly twist in a circular fashion (resulting in a cinnamon-bun look).

Place on Gefen Easy Baking Paper-lined baking sheet.

Repeat until all puff pastry sheets are used up.

Neatly arrange the pinwheels on baking sheets. (A standard baking sheet will fit four across. Do not place too closely together, as they grow during baking.)

The pinwheels may be frozen at this point. When ready to bake, remove from freezer, remove cover, and allow to stand for about 1/2 hour.

Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).

Brush each potato pinwheel well with beaten egg.

Bake for 30–45 minutes, until golden brown and fluffy.