Measure 1 tablespoon of salted butter and set it out so that it comes to room temperature.
Add 6 large eggs to a medium pot, ensuring they all have enough room.
Cover eggs with cold water, enough to cover them by about 1-inch.
Cover pot with a lid.
Bring the pot of eggs to a boil and once the water is boiling, turn off the heat.
Set a timer for 12 minutes.
Prepare an ice bath by adding ice cubes and cold water to a bowl.
Once the twelve minutes are up, carefully remove the eggs and add them directly to the ice bath until they are no longer warm.
Once the eggs have cooled completely, gently peel the shells off of all of the eggs.
Slice each egg in half, longways.
Carefully pop out the cooked yolks into a bowl, using your hands or a spoon.
Add the mayonnaise, pickle juice, truffle sauce, mustard, and softened butter to the bowl of yolks.
Use a fork to mash the yolks and combine until everything is mostly smooth.
Add salt and combine again.
If possible, place filling in the fridge, covered, for at least 30 minutes.
Once chilled, place a piping bag (or ziploc bag) with a grooved tip over a cup and fold the sides down the cup. (This is to hold the bag in place.)
Fill the bag with all of the mixed filling.
Gently fill each egg white with the yolk mixture. You may want to create a swirl design.
Once ready to serve, top each deviled egg with a dollop of caviar (optional).
Additionally, you may garnish with chives or parsley, and a drizzle of truffle oil!