Halve the eggs lengthwise; remove the yolks to a medium bowl.
Consider making the filling using a mini food processor (for the smoothest texture) or mash with a potato masher by hand.
Using the medium bowl containing the egg yolks, mix or mash the yolks, avocado, scallion, mayonnaise, lemon juice and salt together until reaching the desired texture.
Taste and season with more salt, as needed.
Scoop or pipe with a decorative tip back into the egg white halves.
Sprinkle with the everything bagel spice blend and serve.