Make the butter liquid in the microwave or in a saucepan and then stir with the eggs until frothy.
Put the remaining ingredients in a bowl and add the egg and butter mixture. Stir everything.
Put the dough in a muffin pan and bake for 15-20 minutes at 180 degrees.
When the muffins have cooled, the top of the batter is hollowed out so that it looks like a bathtub. Cut one marshmallow at a time into small balls and add to the muffin. Now put the teddy bear in the bathtub.