Preheat your oven to 350°F (175°C). This allows the donuts to rise perfectly as soon as they hit the hot oven.
Lightly grease your donut pan with cooking spray or melted butter to prevent sticking. If you have a silicone pan, you can skip this step as they tend to be non-stick.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt until well combined. Ensure there are no lumps, especially if you chose not to sift your flour.
In another bowl, whisk together the buttermilk, eggs, melted butter, and vanilla extract until smooth. Make sure the butter is not too hot, or it may cook the eggs.
Pour the wet mixture into the dry mixture and gently fold them together until just combined. Be careful not to overmix; a few lumps are perfectly fine!
Using a piping bag or a spoon, carefully fill each cavity of the donut pan about 2/3 full with the batter. This will allow room for the donuts to rise without overflowing.
Place the donut pan in the preheated oven and bake for 10-12 minutes, or until the edges are lightly golden and a toothpick inserted into the center comes out clean.
Once baked, remove the pan from the oven and allow the donuts to cool in the pan for about 5 minutes. Then, gently transfer them to a cooling rack to cool completely.
While the donuts cool, prepare the glaze. In a medium bowl, whisk together the sifted confectioners' sugar, vanilla extract, and enough milk (2-3 tablespoons) until you reach a smooth, pourable consistency. If you want a thicker glaze, add less milk.
Once the donuts are completely cool, dip the tops into the glaze, letting any excess drip off. If you’re feeling festive, sprinkle with food coloring, sprinkles, or glitter while the glaze is still wet.
For an extra touch of sweetness, you can melt some white chocolate chips and drizzle them over the glazed donuts. Allow the chocolate to set before serving.