Melt the chocolate bar with the butter. Mix well and let cool slightly.

In a mixer with a whisk attachment, beat the egg whites with the brown sugar and vanilla extract until semi-stiff peaks form.

Then, by hand, mix in the almond flour, cocoa powder, and baking powder.

Place the batter into a 6-unit mold and sprinkle chocolate chips on top.

Cover with plastic wrap and refrigerate overnight.

The next day, bake at 375°F (190°C) until set. A toothpick should come out like a brownie.

Let cool and enjoy.