Lightly spray egg mold with non-stick cooking spray. Snap mold together and set it on a small tray to catch any spills. Combine jello and boiling water together; stir for 3 minutes until the jello is completely dissolved. Slowly pour mixture into 3 whole eggs (or 6 halves). Repeat as many times as you like, with as many jello flavors you like, until all your eggs are filled. Chill for at least 4 hours.
When you're ready to unmold the eggs, slowly pry the mold halves apart (I use a butter knife to gently coax the halves apart). Using a sharp chef's knife, cut the eggs in half lengthwise using one continuous motion. Next use a melon ball tool to make a well in the large end of each egg half.
(makes enough to fill about 24 egg halves)
8 ounces cream cheese, room temperature
1/2 cup sugar
1 teaspoon vanilla
1/8 teaspoon salt
1/2 cup heavy cream
Cream together the cream cheese, sugar, vanilla, and salt until smooth. Add the heavy cream and whip until stiff peaks form. Put the cream cheese filling into a pastry bag that has been fitted with a star tip and pipe the filling into the egg halves. Chill until service.
Note: To fill the jello eggs with cream cheese filling more than 6 hours ahead of time, add a packet of Whip It to the cream cheese filling mixture when you add the heavy cream.