In a large mixing bowl, cream together 1 cup of softened unsalted butter and ¾ cup of granulated sugar using an electric mixer until light and fluffy, about 2-3 minutes. Add 1 teaspoon of vanilla extract, mixing until integrated.

In a separate bowl, whisk together 2 cups of all-purpose flour and ½ teaspoon of salt. Gradually add the dry mixture to the wet ingredients, stirring gently until just combined.

Cover the bowl with plastic wrap and refrigerate for about 30 minutes.

Preheat your oven to 350°F (175°C). Scoop portions of chilled dough, roll into 1-inch balls, and arrange on a baking sheet. Use your thumb to create an indentation and bake for 10-12 minutes.

In a saucepan over medium heat, add 1 cup of granulated sugar and melt until deep amber, about 5-7 minutes. Carefully add 6 tablespoons of butter and stir, then whisk in ½ cup of heavy cream until smooth.

Fill the cooled cookie indentations with warm caramel and sprinkle with flaky sea salt.