In a 2-3qt sauce pan, combine your butter, brown sugar, corn syrup, and salt.
Melt over medium high heat, stirring constantly, and bring to a boil.
Once boiling, let it boil for 5 minutes without stirring.
After 5 minutes remove from heat, add vanilla and baking soda. Stir until fully combined. The mixture will get lighter in color and start to foam up. That’s normal!
Then slowly pour in your heavy cream, whisking it in as you pour.
Let cool enough to taste, add more salt if it needs it. Also, the caramel will thicken up as it cools!