Wrap a parchment paper or aluminum foil collar around the outside of the individual ramekins; the collar should be about 1 inch above the top of the dish. Secure each collar with a small amount of butter. Place ramekins in the fridge to cool.

In an electric mixer fitted with a whisk attachment, whip the heavy cream until it forms soft peaks. Set aside in the refrigerator.

In a large, heavy saucepan, cook the sugar and water over medium-high heat until it reaches the soft ball stage at 235 to 240 degrees F, about 3 minutes (see Cook's Note**). (Do not overcook the sugar.) Meanwhile, place the yolks into the bowl of an electric mixer and turn to high speed. Slowly add a little of the hot sugar syrup. Decrease speed to medium and add the remaining syrup in a slow, steady stream (see Cook's Note***). Continue to whip for about 5 to 8 minutes, until the mixture is thick and cool. Remove the bowl from the mixer. Whisk in the orange-flavored liqueur and orange zest (see Cook's Note****). Mix in 1/4 of the whipped cream until well incorporated, then fold in the remainder.

Spoon into the ramekins and fill about 1/2-inch above the ramekin. Freeze until set, about 2 hours. Remove the collars and serve.

Cook's Note: *If you don't have a rasp (carpenter's plane), you can finely mince the orange zest. **The soft ball stage is achieved when a drop of the cooked sugar mixture is dropped into cold water and forms a soft ball, but flattens on its own when it's removed. ***Try not to hit the whisk or sides of the bowl with the hot syrup; the syrup can cling to the whisk/bowl and cool, preventing it from fully incorporating into the egg mixture. Pouring the hot syrup towards the side of the mixing bowl will help prevent any hot liquid from being splattered out of the bowl. ****Different flavored oils, extracts, zests, and liqueurs can be used to suit your liking. Alcohol can also be omitted, if preferred.