Preheat your oven to 400F/200C.
Grease either a muffin tin or individual ramekins with baking spray or butter. This will make 9-10, so only grease that many cavities.
Melt the butter and chocolate together then transfer to a large bowl to whisk in the eggs.
The batter will seem liquid at first but as the mixture cools and the eggs incorporate it will thicken and resemble a brownie or cake batter. You will need to whisk strongly to reach this state.
Add the vanilla extract and then whisk in the granulated sugar followed by the flour and salt (if using unsalted butter).
Use a scoop or spoon to transfer the batter to the 9-10 cupcake tins or ramekins. Fill ¾ of the way full.
This batter will not rise when baked.
Bake 8-10 minutes using either convection or the standard setting on your oven.
Let them cool for a few minutes after they come out, and enjoy!
To remove from the pan, place a piece of parchment paper over the top, then a large cutting board or baking sheet. Flip to release!
