Boil 6 large eggs in cool water covering the eggs, then cook for 20 minutes. Transfer to cold water for 2–5 minutes and peel.

Slice eggs in half lengthwise, remove yolks, and push through a mesh strainer to make smooth yolk powder.

Mix yolks with mayonnaise, mustard, salt, and pepper. Adjust consistency with more mayo if needed. Add red food dye or beet juice for a spooky color.

Preheat oven to 350°F (175°C) if using bread. Cut 12 circles from bread slices with a small cookie cutter and flatten. Toast 5–7 minutes until golden. Skip this step if using rice crackers.

Cut a small hole on top of each egg, remove the piece, cut it in half, and place half back into the egg to hold the olive.

Slice olives and insert into eggs.

Turn eggs over and pipe or spoon filling carefully, avoiding overfilling. Place toasted bread or rice cracker on top to seal. Flip back and repeat for all eggs.