Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners and set aside.

In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.

In a large bowl, beat the butter and sugar together using an electric mixer until light and fluffy, about 3-4 minutes.

Add the eggs one at a time, beating well after each addition. Mix in the vanilla extract until fully combined.

Gradually add the dry ingredients to the wet mixture in three additions, alternating with the milk. Start and end with the dry mixture. Mix until just combined—do not overmix.

Divide batter evenly between cupcake liners, filling each about two-thirds full.

Bake for 18-22 minutes, or until a toothpick inserted in the center comes out clean.

Cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

In a medium saucepan, melt the butter over medium heat.

Add brown sugar and heavy cream, stirring constantly. Bring to a boil and cook for 2 minutes.

Remove from heat, then stir in sea salt and vanilla extract. Let cool slightly.

Once cupcakes are completely cool, use a small knife or cupcake corer to remove the center of each cupcake.

Spoon the salted caramel into each cavity, avoiding overfilling. Replace the cupcake tops to seal the filling inside.

Beat butter and cream cheese together until smooth.

Gradually add powdered sugar, one cup at a time, beating until light and creamy.

Mix in vanilla extract and 2 tablespoons of heavy cream. Add more cream if needed to reach the desired consistency.

Pipe frosting over the filled cupcakes, completely covering the centers.

Drizzle each cupcake with caramel sauce and sprinkle lightly with sea salt if desired.

Let the cupcakes rest for a few minutes so the caramel sets slightly. Serve and enjoy the soft cake, creamy frosting, and gooey salted caramel center.