1. Preheat the oven to 425°F or 220°C.

2. Grease a long pan measuring 20x30 cm or 8x12 inches with butter or cooking spray, then line it with parchment paper.

3. In a large mixing bowl, whisk together the sugar, cocoa powder, and salt until well combined.

4. Add the melted butter, eggs, almond flour, cornstarch, and fiber husk to the sugar mixture and mix until a smooth batter forms.

5. Pour the batter into the prepared pan and bake for 20 minutes, or until a toothpick inserted into the cake comes out clean.

6. Meanwhile, prepare the caramel sauce by melting the butter and sugar in a saucepan over medium heat. Add the heavy cream and cook, stirring constantly, until the mixture thickens. Remove the saucepan from the heat and set the caramel sauce aside.

7. Remove the cake from the oven and let it cool for a few minutes. Drizzle the caramel sauce over the warm cake, then return it to the oven for an additional 10-12 minutes, or until the sauce turns golden brown.

8. Remove the cake from the oven and let it cool completely before slicing and serving.