Step 1
Preheat the oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper and lightly grease it.
Step 2
In a large mixing bowl, combine the softened butter and brown sugar until creamy.
Step 3
Mix in the flour, oats, vanilla extract, baking soda, and salt until crumbly.
Step 4
Press about two-thirds of the mixture firmly into the prepared baking pan to form the crust.
Step 5
Bake the crust for 10–12 minutes, until it is lightly golden.
Step 6
Meanwhile, combine the caramel candies and heavy cream in a saucepan over low heat. Stir continuously until smooth. Remove from heat and stir in the vanilla extract and optional sea salt.
Step 7
Pour the warm caramel evenly over the baked crust.
Step 8
Sprinkle the remaining oat mixture evenly over the caramel layer.
Step 9
If desired, sprinkle chocolate chips or chopped nuts over the top.
Step 10
Bake for another 18–22 minutes, or until the topping is lightly golden.
Step 11
Allow the bars to cool completely in the pan, then refrigerate for at least 1 hour before slicing into squares.