Start by getting everything ready. Preheat your oven to 180°C (350°F). Prepare your cake pan by greasing it well and lightly dusting it with flour, or line it with parchment paper so the cake doesn’t stick.
Next, make the wet mixture. Add the carrots, eggs, sugar, vegetable oil, and vanilla extract to a blender. Blend until the mixture is completely smooth and creamy, with no visible carrot pieces.
In a separate large bowl, add the flour, baking powder, and salt. Mix them gently so the ingredients are evenly combined.
Pour the blended carrot mixture into the bowl with the dry ingredients. Using a whisk or spatula, mix slowly just until everything comes together. Stop as soon as you no longer see dry flour—do not over mix.
Pour the batter into the prepared pan and smooth the top if needed. Place it in the oven and bake for about 40 minutes. The cake is ready when a toothpick inserted in the center comes out clean.
Once baked, remove the cake from the oven. Let it cool for a few minutes in the pan, then carefully turn it out onto a plate or cooling rack.
To make the brigadeiro topping, place a saucepan over medium heat. Add the butter, condensed milk, heavy cream, and chopped chocolate. Stir constantly to prevent sticking or burning. Keep stirring until the mixture thickens and becomes shiny, which should take about 10 minutes.
Finally, pour the warm brigadeiro over the cake and spread it gently across the top. Let it sit for a few minutes so the topping sets slightly, then slice and serve.