Air-Fried Cinnamon and Sugar Donuts

Ingredients

• 3/4 cup (165 g) granulated sugar, divided
• 5 tablespoons (75 g) softened butter, divided
• 2 large (40 g) egg yolks
• 2 1/4 cups (280 g) all-purpose flour
• 1 1/2 teaspoons (6 g) baking powder
• 1 teaspoon (5 g) salt
• 1/2 cup (125 ml) buttermilk
• 1 teaspoon ( 2 g) cinnamon
• 2 tablespoons (30 g) butter, melted