I want to buy the filling of Cadbury Creme Eggs to use it in another dessert. I remember that being available but I cannot come up with the keywords to search for it. Maybe something similar is sold by another company with another name?
The keyword you are looking for is "fondant".
Fondant is a soft candy characterized by a smooth texture that comes from small sugar crystals.
It can be as simple as sugar and water boiled to the right temperature and allowed to cool undisturbed. Kind of like fudge without the fat and chocolate.
The filling of Cadbury Creme eggs is called "poured fondant" vs the more solid "rolled fondant" that is often used to decorate cakes.
See this question: What is Fondant?
You can make your own in minutes: (requires wooden spoon and bowl)
400g icing (confectioners) sugar
Mix the water and glucose until smooth, then add the icing sugar until you have the desired consistency, then add the food colouring, if you're making the yellow centre!
You can go the pro route: (requires sugar thermometer and standing mixer)
Heat to sugar to soft ball stage (235-240F/113-116C)
I know which I'd rather do with the kids at Easter!!!
You can make a lower-fat, minimally-processed version by whipping together cream cheese and powdered sugar: