Rub yeast and combine with flour in a large bowl. Add milk, eggs, sugar, honey, and salt, and mix until well combined. Add butter, and keep on mixing
When the dough has pulled together, turn it out onto a lightly greased surface (it is a quite sticky dough), and knead with greased hands until smooth and elastic, about 10 minutes.
Shape into a ball, and let the dough rest in the same bowl you've used before until it has doubled its size, it will take from 1 to 2 hours.
Divide dough into equal pieces. Then divide each pice into 3 pieces: a big one for the head, and two smaller ones for the ear.s Shape into smooth balls, and place on a greased baking sheet, forming Mickey Mouse's head. Ears should be about 0,5 cm away from the head, they will get together when the dough rises. Let it rest for 30 minutes.
Preheat oven 200 ºC (400ºF). Milk wash the buns, and bake for 10 minutes at 180ºC. Let them cool on a wire rack.
Prepare the buttercream. Heat water and sugar in a casserole, until it begins to boil. Let this sugar syrup cool. Cream butter, and beat on medium speed while gradually adding the syrup, until light and fluffy. Fill the buns with the buttercream and enjoy!