In a large mixing bowl, combine self-raising flour and sweetened Greek yogurt. Stir until a soft dough forms.

Transfer the dough onto a floured surface and knead it gently for about 1-2 minutes until smooth.

Divide the dough into two equal portions; roll each into a long log about 1-inch thick and cut into small pieces weighing approximately 8-12 g each.

Roll each piece into smooth balls for uniformity in shape.

Preheat the air fryer to 180°C (350°F) for about 5 minutes. Brush the basket with oil to prevent sticking.

Toss the donut balls in melted butter and place them in the air fryer basket, leaving space for air circulation.

Air fry the donut bites for about 5 minutes until puffed and golden brown. Shake the basket halfway through.

Coat the warm donut bites in melted butter and roll in the cinnamon-sugar mixture until fully covered.