In a separate bowl, combine the sugar with the melted butter, then add the yogurt, apple cider, and applesauce. Add the dry ingredients to the wet ingredients and stir until just combined.
⅓ cup (66g) granulated sugar, 3 tablespoons unsalted butter, ½ cup (112g) Greek yogurt, ½ cup (120ml) apple cider, ¼ cup (64g) unsweetened applesauce
Spoon or pipe the batter into prepared donut pan. Bake for 12-15 minutes. Allow donuts to cool in the pan before removing and adding cinnamon sugar topping.
Cinnamon sugar topping:
Melt the butter in a small, microwave-safe bowl. In a separate bowl, mix the sugar and cinnamon together. Dip each donut in the melted butter, then in the cinnamon sugar mixture.
4 tablespoons (56g) unsalted butter, ½ cup (100g) granulated sugar, ½ teaspoon cinnamon