Mix yeast, warm water, sugar, evaporated milk, salt, shortening, eggs, and vanilla in a stand mixer's bowl. Start with 2 cups of flour and knead on medium-low using the dough hook until combined. Gradually add more flour until the dough is smooth and slightly sticky but not too sticky to handle.

Move the dough to a lightly greased bowl, cover with plastic wrap or a clean towel, and let it rise for about 1 1/2 hours.

On a lightly floured surface, roll the dough to a thickness of 1/4 to 1/2 inch. Cut out 12 donuts using a round cutter or a glass, re-rolling the scraps as needed. Let the cut donuts rise for another 30 minutes.

Preheat the air fryer to 350°F. Place 3-4 donuts in the air fryer basket, ensuring they don’t touch. Lightly spray the donuts with cooking spray and air fry for about 4 minutes, flipping halfway through. Test with one donut to ensure they are cooked through.

Transfer the cooked donuts to a wire rack with paper towels underneath. Allow them to cool for 1-2 minutes. For glazed donuts, dip the tops into the glaze and return to the rack. For cinnamon sugar donuts, dip each donut in melted butter and then into a cinnamon sugar mixture, coating both sides, and return to the rack.