Press the mixture into the bottom of a 9x13-inch baking pan. Bake the crust for 10 minutes. When the crust is done baking, let it cool on a wire rack for 20 minutes.

While the crust is cooling, make the caramel. In a medium pot, add the rest of the butter (½ cup) to the pan.

Add the brown sugar, sweetened condensed milk, and ½ teaspoon sea salt, and then stir to combine.

Over medium heat, allow the caramel to come to a boil. Let the caramel gently boil, while stirring constantly, until the mixture reaches 240 degrees F. on a candy thermometer, about 10 minutes.

Remove from the heat, and stir in the vanilla.

Pour the caramel over the cooled crust, and then spread it out evenly. Let it cool for 30 minutes.

While the caramel is cooling, make the chocolate ganache. In a small saucepan, bring 1 cup of heavy whipping cream to a boil over medium-high heat. Remove the pan from the heat, and then add all of the chopped chocolate.

Let the chocolate sit in the hot cream for about 30 seconds, and then stir until melted.

Pour the ganache over the caramel, and spread smooth with a spatula. Sprinkle the hot chocolate with a little more sea salt, about ¼ teaspoon.

Refrigerate the tart until set, about one hour.

Beat the rest of the whipping cream to make whipped cream to serve on top. When you are ready to serve, remove the tart from the fridge, and let it sit at room temperature for about 20 minutes before serving.

Serve with a dollop of whipped cream.