In a mixing bowl, gently stir warm milk, yeast and 1 tbsp of sugar together. Wait 10 minutes for it to start to foam.

Add egg, melted butter and remaining sugar. Stir until completely combined.

Using a dough hook in an electric mixer, add the flour slowly allowing it to mix on low. Once mixed, increase speed to medium and knead it until dough forms into a ball.

Once dough has risen, remove and roll dough out to ½ inch thick on a floured surface.

Using a circle cutter or a wide mouth mason jar, cut 10-12 donuts out. Using a smaller hole cutter, punch out a hole in each donut.

Place donuts on a rack that has been placed on a baking sheet, and cover with plastic wrap. Allow the donuts to rise for 20 minutes.

Place two or three donuts in air fryer basket leaving them room to expand. Spray the donuts with oil and cook on 350F/176C for 4 minutes on each side.

Remove donuts and using fork, dip the donuts halfway into the frosting. Place back on the rack to let sit.