Preheat your oven to 350°F (180°C) and line a small baking pan with parchment paper.
In a saucepan, melt the butter and dark chocolate over low heat, then let it cool slightly.
In a bowl, whisk together the granulated sugar and eggs until light and fluffy.
Pour in the melted chocolate-butter mixture, add the vanilla extract, and stir until smooth.
Sift in the flour, baking powder, and salt, then add the ground walnuts and gently fold until just combined.
Pour the batter into the prepared baking pan and sprinkle the top with the roughly chopped walnuts.
Bake in the preheated oven for about 25-30 minutes, until the top is set but the inside is still slightly fudgy.
Let it cool completely in the pan, then slice and serve.
To provide the best experiences, we and our partners use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us and our partners to process personal data such as browsing behavior or unique IDs on this site and show (non-) personalized ads. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Click below to consent to the above or make granular choices. Your choices will be applied to this site only. You can change your settings at any time, including withdrawing your consent, by using the toggles on the Cookie Policy, or by clicking on the manage consent button at the bottom of the screen.