Combine the cream cheese and water in a medium bowl and microwave for one minute.
Whisk together until smooth.
The mixture will be a little frothy, that's ok.
Add your sugar free syrup and egg yolks and whisk together until smooth.
Microwave on high for 30 seconds, then whisk.
Repeat this 3 more times or until your mixture has thickened (if you are making a double batch, it will take 5 or 6 times at 30 seconds each.)
Chill your mixture in the refrigerator or freezer until cold, then process in your ice cream maker according to the mfg instructions.
If you don't have an ice cream maker, simply freeze until firm, or try using the baggie method
Standard Custard Versus This Method
Traditional frozen custard relies on a cooked base of milk, cream, and egg yolks thickened slowly on a stovetop. This variation replaces dairy liquids with water and cream cheese, using intermittent microwave heating to thicken the yolks without curdling them. Whisking vigorously between each thirty-second burst prevents the proteins in the egg yolks from clumping into scrambled bits.
Equipment and Chilling Mechanics
An electric ice cream maker yields the smoothest texture by incorporating air while crystals form. Pour the liquid base into the machine only after it reaches a temperature below 40 degrees Fahrenheit. Without a machine, place the mixture in a shallow metal pan in the freezer, scraping the edges every twenty minutes with a fork to break up ice formations.
Sequencing in the Kitchen
Plan for at least one hour of total processing time, factoring in both the initial heating cycles and the final freeze. Chill the blended base thoroughly before churning because warm fat coats the churn blades poorly and delays freezing. Store the finished dessert in an airtight container for up to three days.