Add the flour, sugar, yeast and salt to a large bowl. Mix to combine and then add the egg, oil, and warm water. Mix until a dough forms. Turn the dough out onto a table and knead for 5 minutes, until dough is soft and smooth. Place the dough in a greased bowl and cover. Place in a warm part of the room and allow the dough to rise until doubled in size, about 45 mins. Remove dough from bowl onto a floured surface. Roll out the dough to ½ inch thickness. With a cookie cutter or drinking glass, cut 2-inch circles in the dough. When you are left with scraps of dough, roll it out again and cut more circles. Preheat your June oven on air-fryer mode to 350℉/175℃. Place dough circles on a greased air fryer sheet pan. Brush the dough generously with oil. Cover with a towel for 30 minutes to allow doughnuts to rise. Cover an air-fryer tray with aluminum foil and place it in the lowest rack of the oven. Place the doughnuts in the oven on the middle rack. Air-fry for 5 minutes until puffed up and golden brown. June will alert you once the 5 minutes are up! Remove from oven and allow to cool before handling.  Topping options: Dip each doughnut in melted milk chocolate and place pretzel pieces on top. Dip each doughnut in melted white chocolate and sprinkle the rainbow sprinkles on top. Use a squeeze tube or piping bag to fill the doughnuts with strawberry jam. Garnish with powdered sugar.