In a large bowl, combine the sourdough starter, whole milk, egg, raw cane sugar, melted butter, vanilla, and salt. Stir until smooth.

Gradually add the bread flour, mixing until a soft dough forms. If the dough is too sticky, add a little more flour.

Cover the dough with a clean kitchen towel and let it rise in a warm place for 60-120 minutes, or until it has doubled in size.

Turn the dough out onto a floured surface. Roll it out to about 1/2 inch thick. Use a donut cutter or two round cutters to cut out donuts and holes.

Place the cut donuts on a floured baking sheet. Cover them loosely with a towel and let them rise for another 30-45 minutes.

Heat the coconut oil in a deep frying pan to about 350°F (175°C) and fry the donuts until golden brown on both sides, about 1-2 minutes per side. Remove and drain on paper towels.

For a baked version, preheat your oven to 375°F (190°C). Place the donuts in a greased donut pan and bake for about 10-12 minutes or until lightly golden.

In a bowl, mix powdered sugar and whole milk to create a smooth glaze. Dip each donut into the glaze while they are still warm.