Square Deviled Eggs

Directions

1. 1
   Special equipment: a pastry bag fitted with a small round pastry tip
2. 2
   Preheat the oven to 350 degrees F. Coat an 8-inch square baking dish with cooking spray.
3. 3
   Separate the egg whites and yolks into 2 small bowls; set aside the yolks.
4. 4
   Whisk the whites until just foamy, transfer them to the prepared baking dish, cover the dish with foil and bake until the whites have fully set, about 20 minutes.
5. 5
   Let cool completely in the baking dish.
6. 6
   While the whites are baking, beat the yolks until smooth.
7. 7
   Lightly coat a medium nonstick skillet with cooking spray.
8. 8
   Add the yolks, and scramble over medium low until fully cooked and slightly dry, 4 to 5 minutes.
9. 9
   Transfer the yolks to a food processor.
10. 10
    Add the mayonnaise, vinegar, mustard, 1/4 teaspoon salt and a few grinds of pepper, and pulse until smooth and creamy.
11. 11
    Transfer the yolk mixture to a pastry bag fitted with a small round tip.
12. 12
    Turn the egg whites out of the baking dish onto a cutting board.
13. 13
    Cut into even 1-inch squares.
14. 14
    Pipe swirly dollops of the egg yolk onto each square.
15. 15
    Sprinkle each with paprika and chives if using.