Preheat your oven to 350°F (175°C) and prepare a mini muffin tin by greasing it or lining it with mini cupcake liners.

In a medium saucepan, melt the unsalted butter over low heat. Once melted, remove from heat and stir in the granulated sugar until well combined.

Allow the mixture to cool slightly, then add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In a separate bowl, whisk together the all-purpose flour, cocoa powder, and salt. Gradually add this dry mixture to the wet ingredients, stirring until just combined.

Spoon a small amount of brownie batter into each mini muffin cup, filling them about halfway. Add a teaspoon of caramel sauce on top, then cover with more brownie batter until the cups are about 3/4 full.

Bake in the preheated oven for 15-18 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.

Let the brownie bites cool in the pan for about 10 minutes before transferring them to a wire rack to cool completely. Drizzle additional caramel sauce on top and sprinkle with sea salt before serving.