Preheat your oven to 325°F / 165°C with the rack in the middle.

Grease a muffin pan with butter (for flavour) and then coat each hole with cocoa powder.

Next, chop up the semi-sweet chocolate and slice the unsalted butter into several large pieces.

Melt them together in a saucepan over low heat, stirring occasionally. As soon as it has melted remove the pan from the heat and set it aside.

Sift the flour, Dutch-processed cocoa powder, and salt into a small bowl and set them aside.

Crack the eggs into a bowl and add in the sugar and vanilla extract. Whisk them together very well until they become thick and pale in colour.

Stir in the melted chocolate and butter mixture.

Then mix in the dry ingredients and stir until just incorporated.

Spread the batter evenly into the prepared muffin pan.

Bake them for about 15-17 minutes (oven times can slightly vary). Mine were ready in 16. Pull them from the oven before an inserted toothpick comes out clean. You absolutely do not want to over-bake them. Doing so will cause them to lose their chewy texture and become more cake-like.

Let them cool in the pan for 10 minutes. They will sink down even more as they set, forming dense and chewy brownie cupcakes.

Carefully transfer them to a cooling rack to cool the rest of the way.