Step 1

In a large saucepan, whisk together sugar and cornstarch until combine. Pour in cream, milk and corn syrup and whisk until well blended. Cook mixture over medium heat (sometimes I even cook it over medium high to speed it up a bit), stirring constantly until mixture comes just to a gentle boil.

Step 2

Once mixture reaches a gentle boil, reduce heat and allow mixture to gently bubble, stirring constantly, for 30 seconds. Strain mixture through a fine mesh sieve into a large bowl. Cover mixture with saran wrap or wax paper, pressing directly against the surface of the ice cream base to prevent a skin from forming.

Step 3

Refrigerate mixture until fully chilled, then transfer to freezer and freeze 1 hour - 1 1/2 hours (I've found this really helps the ice cream structure when freezing post ice cream maker processing, it basically gives it a head start). Transfer extra chilled ice cream mixture to an ice cream maker and freeze according to manufacturers directions.

Step 4

Transfer ice cream to an airtight container and freeze until nearly firm, or freeze until firm and soften in microwave about 5-10 seconds until slightly softened. Mix in desired "mix-ins" (if you wanted to prepare just as Cold Stone does, you could freeze a marble slab then use two large spoons to fold in mix-ins using chilled marble slab, or alternately you could add the mix-ins in during the last 5 minutes of processing in ice cream maker).