Warm the milk, add sugar and yeast, and let it sit for 5 minutes until foamy.
In a bowl, mix flour, salt, sugar, egg, and yeast mixture. Combine into dough.
Add butter and knead for 8–10 minutes until smooth and elastic.
Place dough in a greased bowl, cover, and let it rise for 1–1.5 hours until doubled.
Roll out the dough to ½ inch thickness and cut into round shapes.
Let the shaped dough rest for 30–40 minutes until puffy.
Heat oil to 170–175°C and fry donuts for 2–3 minutes per side until golden.
Remove and cool completely on a wire rack.
Whip cream with sugar and condensed milk until stiff peaks form.
Slice donuts and fill generously with cream using a piping bag.
Serve fresh for best texture and flavor.
