1. Cut two 8x16" pieces of parchment. Lay pieces perpendicular to each other in an 8" square baking dish with excess hanging over sides to form a sling. Coat parchment and any exposed areas of pan with cooking spray and set aside.
2. Bring cream, butter, and salt to a simmer in a small saucepan over medium heat, stirring occasionally. Remove from heat, cover to keep warm, and set aside.
3. In a large saucepan, combine corn syrup and water. Slowly add sugar to center of pot, being careful to avoid sides. Without stirring, bring mixture to a boil over medium-high heat. Cover and cook 3 minutes, then uncover and continue to cook, without stirring, until mixture registers 300 degrees, 5 to 7 minutes.
4. Reduce heat to medium-low and cook, swirling pan occasionally, until bubbles have shrunk in size and mixture is amber in color and registers 350 degrees, 2 to 3 more minutes. Remove from heat and stir in cream mixture, taking caution as caramel will quickly foam up sides of the pot. When foaming has slowed, return to medium-low heat and cook, stirring and scraping bottom of pot constantly, until mixture is the color of butterscotch and reaches 248 degrees, about 7 minutes.
5. Remove from heat and whisk in vanilla, then pour into prepared pan and let sit 10 minutes; sprinkle evenly with sea salt. Let cool at room temperature 1 hour, then refrigerate 1 more hour.
6. Using parchment sling, lift caramel out of pan and transfer to a cutting board. Slice into 1" squares or 1 1/4"-long rectangles, then wrap each piece in waxed paper. Store in an airtight container at room temperature for up to 3 weeks or freeze for up to 6 months.
Source: Hannaford fresh Magazine, December 2020