Preheat and prepare:
Preheat your oven to 350°F (175°C). Line a 9×9” baking dish with parchment paper and lightly grease it. Set aside.

Make the caramel:
In a medium saucepan, combine the heavy whipping cream and caramels. Warm over medium heat, stirring constantly, until the caramels melt into a smooth sauce. Transfer to a glass measuring cup or bowl and allow to cool slightly.

Prepare the brownie batter:
In a small bowl, whisk together the flour, cocoa powder, and sea salt. In a microwave-safe bowl or over low heat on the stove, melt the semisweet chocolate and butter together until smooth and glossy. Set aside.
In the bowl of a stand mixer, beat the eggs on medium speed for 1 minute, until pale and thick. Gradually add the sugar, beating for another 30–60 seconds until dissolved. Mix in the melted chocolate and butter, then add vanilla and stir on low speed until the batter is smooth and uniform.
Add the dry ingredients and mix just until incorporated, taking care not to overmix.

Assemble the layers:
Pour two-thirds of the brownie batter evenly into the prepared pan. Carefully pour the caramel layer over the batter, spreading evenly. Dollop or gently spoon the remaining brownie batter over the caramel, covering as much as possible.

Bake and cool:
Bake in the preheated oven for 25–30 minutes, or until the top is set and the brownies still have a slight jiggle in the center. Remove from the oven and immediately sprinkle the top with flaky sea salt.
Place the pan on a wire rack and allow the brownies to cool completely before cutting into squares and serving.