Mix the dry ingredients in a large bowl: flour, sugar, baking powder, and salt until well blended.

Whisk the wet ingredients in a separate bowl: eggs, milk, and melted butter until smooth and creamy.

Combine the wet and dry mixtures gently until just combined, being careful not to overmix.

Preheat your fryer or oil in a deep pan to 350°F (175°C).

Spoon dollops of batter into the hot oil, frying them in batches for about 2-3 minutes per side until golden brown.

Remove the donuts from the oil using a slotted spoon and let them drain on paper towels.

Coat each warm donut generously in sugar to create a sweet crust.