Combine egg and egg yolks in a medium bowl; beat well with a whisk.
Whisk together sugar, cornstarch, and salt in a Dutch oven until blended. Whisk in milk; bring to a simmer over medium heat, whisking constantly. Remove from heat. Gradually whisk about one-fourth of hot mixture into eggs; add to remaining hot mixture, whisking constantly. Cook over low heat 6 minutes or until thick. Remove from heat; whisk in coffee creamer, condensed milk, and cream. Cool completely; cover and chill thoroughly.
Pour mixture into freezer container of a 4-quart ice-cream maker, and freeze according to manufacturer's instructions. (Freezing instructions will vary among manufacturers.) Pack freezer with additional ice and rock salt, and let stand 1 hour before serving.
*For testing purposes only, we used Coffee Mate liquid coffee creamer.
Tip: After processing in ice-cream maker, pour ice cream into a plastic container, and place in freezer to harden to desired consistency. It will take at least 3 hours to become firm, depending on the depth of container used.