Preheat your oven to 350°F (175°C).
In a bowl, cream together the softened butter and brown sugar until light and fluffy.
Add the egg and vanilla extract, mixing until well combined.
In another bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, stirring until combined.
Scoop tablespoon-sized portions of the dough and place them on a lined baking sheet, leaving space between each.
Use your thumb to make an indentation in the center of each cookie.
Fill each indentation with caramel sauce.
Bake in the preheated oven for 12-15 minutes, or until the edges are lightly golden.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack.
Sprinkle with optional crushed nuts or sea salt before serving, if desired.
