Make the white icing: whisk the powdered sugar, 3 tablespoons of milk and vanilla extract together until smooth and pourable but not watery. Add the fourth tablespoon of milk only if the glaze is too thick to coat.

Set the wire rack over a baking sheet to catch drips.

Drop one donut hole into the icing bowl, turn it with a fork to coat all sides, then lift it out and let the excess icing drip off.

Place it on the wire rack and immediately press one large candy eyeball into the top.

While the icing is still wet, use the red edible pen or a toothpick dipped in red gel to draw thin red veins radiating out from the eyeball.

Repeat with all remaining donut holes.

Let the glaze set for 10 to 15 minutes before stacking on a serving plate.