For the Cupcakes:

1. Preheat the oven to 350°F (175°C). Line a cupcake tin with cupcake liners.
2. In a medium bowl, whisk together the flour, baking powder, and salt.
3. In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
4. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
5. Gradually add the dry ingredients to the butter mixture, alternating with the milk, mixing until just combined.
6. Divide the batter evenly among the cupcake liners, filling each about two-thirds full.
7. Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Let the cupcakes cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.

For the Caramel Sauce:

1. In a small saucepan, combine the heavy cream, butter, brown sugar, and salt over medium heat. Stir until the butter is melted and the sugar is dissolved.
2. Bring the mixture to a simmer and cook for 4-5 minutes, stirring frequently. Remove from heat and let it cool slightly.
3. Once cooled, mix in the powdered sugar until smooth and well combined. Set aside.

For the Cream Cheese Frosting:

1. In a large bowl, beat together the softened cream cheese and butter until smooth and creamy.
2. Gradually add the powdered sugar, one cup at a time, mixing until fluffy.
3. Stir in the granulated sugar, butter, heavy cream, and vanilla extract. Beat until the frosting is smooth and well combined.
4. Add the sea salt and mix to incorporate.

Assemble the Cupcakes:

1. Once the cupcakes have cooled completely, use a spoon or piping bag to frost the cupcakes with the cream cheese frosting.
2. Drizzle the caramel sauce over the frosted cupcakes and sprinkle with sea salt for the perfect finish.