Mix Dry Ingredients: In a bowl, whisk flour, sugar, baking powder, salt, and nutmeg.
Combine Wet Ingredients: In another bowl, beat eggs, milk, melted butter, and vanilla.
Make Dough: Gradually add wet ingredients to dry, mixing until just combined (do not overmix).
Roll & Cut: On a floured surface, roll dough to 1/2-inch thickness. Cut into donut shapes.
Heat Oil: Fill a pot with 2–3 inches of oil; heat to 350°F (175°C).
Fry Donuts: Fry 2–3 donuts at a time for 1–2 minutes per side until golden. Drain on paper towels.
Coat/Glaze: While warm, toss in cinnamon sugar or dip in glaze.