Combine dry ingredients:
In a medium bowl, combine the flour, sugar, baking powder, and salt with a whisk.Mix wet ingredients:
In a liquid measuring cup, mix together the milk, oil, and egg; whisk until uniform.Knead dough briefly:
Add the wet mixture to the dry ingredients and stir until a dough comes together. Knead for 30–60 seconds until cohesive, avoiding overkneading to retain the air from the baking powder.Shape and cut dough:
Shape the dough into a rectangle 3/4-inch (2 cm) thick. Use a cutter to form circles; set them on a baking sheet.Prepare sugar coating:
Place 1/2 cup (100 g) sugar in a shallow bowl and set aside.Fry and coat doughnuts:
When ready, heat 1 inch (2.5 cm) of oil to 325°F (165°C) in a Dutch oven or heavy pot. Fry the dough pieces for 2–3 minutes per side until golden. Remove and toss in the sugar to coat evenly. Enjoy!