How to cook
Place paper forms in a muffin tray and preheat the oven to 360°F (180 °C). Stir the soft butter with the sugar, gradually add the eggs, vanilla, cocoa and buttermilk. Stir everything well and begin to gradually add the flour that you've sifted with the salt and baking soda.
Stir with a spatula and then add the 3 types of chocolate that have been chopped or cut into small pieces . Fill the molds with the mixture up to 2/3 of their height. Put them to bake for about 20-25 minutes. The muffins should end up slightly moist with a heavy texture, not dry and crumbly.
Check to see how moist they are in the 20th minute of baking, they need to be slightly damp. Let the muffins cool for 10 minutes and take them out of the muffin tray.