Warm the milk until it's lukewarm. Add the yeast and a pinch of sugar. Let it sit for 5 minutes until frothy.
In a large mixing bowl, combine the flour, sugar, and salt. Add the beaten eggs, melted butter, and the yeast mixture. Mix until a dough forms.
Knead the dough on a floured surface for about 10 minutes until smooth and elastic. Place the dough in a greased bowl, cover, and let it rise for 1 hour or until doubled in size.
Heat the vegetable oil in a frying pan to 350°F (175°C). Shape the dough into small balls and fry them in batches until golden brown, about 2-3 minutes per side.
Remove the malasadas with a slotted spoon and drain on paper towels. Roll them in sugar while still warm. Serve immediately.