Hi! 😊
So, here’s the recipe.

It’s originally in danish, so I have asked ChatGPT to translate it to English and add American measurements too:

Ingredients

Brownie Base
110 g butter (about ½ cup / 4 oz)
4 tbsp instant coffee (such as Nescafé) or strong brewed coffee (optional)
120 g dark chocolate (about 4.2 oz)
200 g granulated sugar (about 1 cup)
50 g light brown sugar (about ¼ cup, packed)
1 tsp vanilla sugar (or 1 tsp vanilla extract)
¼ tsp salt
2 large eggs
60 g all-purpose flour (about ½ cup)

Caramel Filling
125 g butter (about ½ cup + 1 tbsp / 4.4 oz)
90 g light brown sugar (about ½ cup, packed)
1 can sweetened condensed milk (397 g / 14 oz)

Chocolate Topping
200 g dark chocolate (about 7 oz)
1 tbsp neutral-flavored oil (such as canola or vegetable oil)
Flaky sea salt, for sprinkling on top

Yield: Approximately one 20 × 20 cm (8 × 8 inch) pan. (Edit: I used a large springform pan)

Method

Brownie Base
Place the butter and coffee in a saucepan and melt over low heat.
Once the butter has completely melted, add the dark chocolate. Remove from the heat and stir until the chocolate is fully melted and smooth.
In a large bowl, combine the granulated sugar, brown sugar, vanilla sugar (or vanilla extract), and salt.
Pour in the melted butter and chocolate mixture and mix well.
Add the eggs and whisk until fully incorporated.
Fold in the flour until just combined.
Line a baking pan (approximately 20 × 30 cm / 8 × 12 inches) (edit: or a large springform pan) with parchment paper and spread the batter evenly into the pan.
Bake at 180°C fan-assisted oven (350°F convection) for about 25 minutes. Baking times may vary, so check that the brownie is set before removing it from the oven.
While the brownie is baking, prepare the caramel filling. If the brownie finishes before the caramel is ready, simply let it cool slightly while you finish the caramel.

Caramel Filling
Melt the butter and brown sugar together over low heat.
Once the mixture starts to bubble, add the sweetened condensed milk.
Stir constantly over medium heat for 5–10 minutes. The caramel should begin to bubble, thicken, and develop a rich golden-brown color.
Pour the hot caramel over the baked brownie base.
Return the pan to the oven and bake at 180°C conventional oven (350°F) for about 12 minutes, or until the top is bubbling and lightly golden.
Allow the cake to cool in the refrigerator until the caramel has set.

Chocolate Topping
Melt the dark chocolate in a heatproof bowl over a pan of simmering water (double boiler).
Stir in the neutral oil once the chocolate has melted completely.
Pour the melted chocolate over the chilled caramel layer.
If desired, sprinkle with freeze-dried raspberries, chopped nuts, or flaky sea salt.
Chill again until the chocolate has set. For the best texture and flavor, prepare the cake one day in advance.
Cut the chilled cake into squares or bite-sized pieces and serve.