Prepare the Cupcakes:
Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
In a medium bowl, whisk together the flour, baking powder, and salt.
In a large bowl, beat together the softened butter and sugar until light and fluffy, about 3 minutes.
Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, alternating with the milk. Start and end with the dry ingredients, mixing until just combined.
Stir in the caramel sauce until well incorporated.
Divide the batter evenly among the cupcake liners, filling each about 2/3 full.
Bake for 18-22 minutes, or until a toothpick inserted into the center comes out clean.
Let the cupcakes cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.
Prepare the Salted Caramel Frosting:
In a large bowl, beat the softened butter until creamy.
Add the caramel sauce, powdered sugar, and salt, and beat until the frosting is smooth and fluffy.
Add the heavy cream, 1 tablespoon at a time, until you achieve your desired consistency for spreading or piping.
Once the cupcakes have cooled completely, frost them with the caramel buttercream frosting using a piping bag or spatula.
Optional Caramel Drizzle:
Drizzle the top of each frosted cupcake with additional caramel sauce for a sweet, gooey finishing touch.