Preheat your oven to 350°F. Line a 9x13-inch baking pan with parchment paper.
For the shortbread base, combine flour and sugar in a food processor. Add cold butter cubes and pulse until the mixture resembles coarse crumbs.
Press the mixture firmly into the bottom of the prepared pan. Bake for 20-22 minutes until lightly golden. Remove and set aside.
While the base bakes, make the caramel. In a medium saucepan, combine butter, brown sugar, honey, and heavy cream.
Bring to a boil over medium heat, stirring constantly. Once boiling, continue to cook for 5 minutes without stirring.
Remove from heat and stir in vanilla extract. Pour the hot caramel over the baked shortbread base.
Immediately sprinkle flaky sea salt over the top to your liking.
Bake for an additional 15 minutes until the caramel is bubbling.
Let cool completely at room temperature for at least 2 hours, then refrigerate for 1 hour before cutting into squares. Store in an airtight container for up to 1 week.