As always when it comes to muffins, combine all the liquid ingredients (egg, milk, oil) in one bowl and the dry ones (flour, sugar, cocoa, yeast) in another.

Then pour the liquid ingredients over the dry ones and mix quickly, then add the chocolate and marshmallows.

Spread the mixture into molds (silicone, or greased and floured, or lined with cups, you see) until they are 3/4 full and cook for 15-20 minutes in a preheated convection oven at 180 ° C.

That's it: the marshmallows and chocolate muffins are ready to taste.