In a small bowl, dissolve yeast in warm water with a pinch of the sugar. Set aside until foamy, about 10 minutes.
Transfer the yeast mixture to a large bowl, and stir in the sugar, eggs, salt, flour and milk until the dough comes together. Stir in the butter, then turn the dough out onto a floured surface, and knead for about 10 minutes, or until smooth and elastic. Cover dough with a cloth and set aside to rise until doubled in bulk, about 45 minutes.
Divide dough into about 15 to 20 pieces, and shape them into flat round cakes about 1cm (1/2 in) thick. Place a cloth on the table and dust it with flour. Arrange the cakes on the cloth, allowing space for rising. Allow them to sit for 1 1/2 hours.
Place the cakes in a heavy ungreased frying pan, and cook over low heat. Fry the cakes on each side until golden.