Step 1: Prepare the Cupcake Batter

1. Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
2. In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
3. In a large mixing bowl, beat the butter and sugar with an electric mixer 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 wet mixture, alternating with the milk, beginning and ending with the dry ingredients.
6. Fold in the caramel sauce until just combined—do not overmix.

Step 2: Bake the Cupcakes

1. Divide the batter evenly among the cupcake liners, filling each about ⅔ full.
2. Bake for 18-20 minutes, or until a toothpick inserted in the center comes out clean.
3. Remove from the oven and let the cupcakes cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

Step 3: Make the Caramel Drizzle

1. In a small saucepan, heat the granulated sugar over medium heat, stirring constantly until it melts and turns a deep amber color.
2. Add the butter, stirring until fully melted.
3. Slowly pour in the heavy cream, stirring continuously (be careful—it may bubble up).
4. Remove from heat, stir in the sea salt, and let cool before using.

Step 4: Prepare the Salted Caramel Buttercream

1. In a large bowl, beat the butter until creamy.
2. Gradually add the powdered sugar, beating on low speed until incorporated.
3. Mix in the caramel sauce, sea salt, vanilla extract, and heavy cream, beating until smooth and fluffy. Adjust with more cream if needed for consistency.

Step 5: Assemble the Cupcakes

1. Once the cupcakes are completely cool, pipe the buttercream onto each one using a piping bag with a star tip.
2. Drizzle with the homemade caramel sauce and sprinkle with flaky sea salt or crushed caramel candies.
3. Let set for a few minutes before serving.