Yes! I was able to make a panna cotta using this product in a standard recipe with some minor changes. Just incorporate the Jell Dessert powder where the gelatin is called for and subtract 1/4-cup from the prescribed sugar.
I started with this recipe on JoyofBaking.com.
The recipe, like most I've seen, calls for one standard 1/4-ounce packet of gelatin. From what I've read (e.g. here) this amount is used to gel 2 cups of water in standard application. The preparation directions for the Jell Dessert also call for 2 cups of water, so it probably contains an equivalent amount of gelling power to a standard packet of gelatin.
The main ingredient in the Jell Dessert powder that isn't a gelling agent is sugar. As sugar is also a major ingredient in panna cotta, I figured that I could try cutting the sugar by the sugar content of the Jell Dessert. I estimated this amount by observing that the Jell Dessert is two thirds sugar by weight (14 g of each 21 g serving, according to the Nutrition Facts), measuring the total volume of the powder at a bit more than 1/3-cup, and assuming that all of its ingredients are of similar density. A little more than two thirds of 1/3-cup is 1/4-cup.
So, I made the following substitutions to the standard recipe:
When the recipe calls for sprinkling the gelatin onto cold milk, I instead mixed the Jell Dessert powder with the milk. I mixed instead of just sprinkling because I was afraid that the additional ingredients would clump around the gelling agents and prevent them from getting properly wet, otherwise.
I cut the powdered sugar to cook with the cream from 1/2-cup to 1/4-cup.
The result was, as far as I could tell, a successful, strawberry-flavored panna cotta. I'd never tasted panna cotta before, so I didn't have a basis for comparison, but it set nicely, was pleasantly creamy, didn't taste too sweet to me (at least, as served with semi-sweet chocolate sauce), and was, in my opinion, delicious.
I expect that the same substitutions would work for this product in other panna cotta recipes. I'm not as sure whether other prepared Jell Desserts (including Jell-O) would work the same way or not.