Preheat the oven to 375 (190 C). Grease two 6 ct. donut pans. In a large bowl, whisk the flour, baking powder, ground cinnamon, ground ginger, ground nutmeg, ground cardamom and salt together until well combined.
2 cups (240 g) all purpose flour, 2 teaspoons baking powder, 1 teaspoon ground cinnamon, ¼ teaspoon ground nutmeg, ginger and cardamom, ½ teaspoon salt
In another large bowl, pour the whisk the melted butter, light brown sugar, an egg, buttermilk, and applesauce together until smooth and well combined. Mix the dry ingredients to the wet until well combined. Peel and shred an apple. Mix the shredded apple into the donut batter.
½ cup (120 g) applesauce, ½ cup (120 ml) buttermilk, room temperature, ½ cup (100 g) light brown sugar, ¼ cup (60 ml) melted and slightly cooled butter, 1 large egg, room temperture, ¾ cup shredded apples
Spoon or pipe the apple donut batter into each of the prepared donut cavities in the donut pan. This should fill about ¾ of each cavity of the donut pan.
Bake the donuts for about 12 - 14 minutes. The donuts are done when the tops bounce back quickly when lightly pressed. Cool the donuts in the pan for 5 minutes before gently taking them out to cool on a cooling rack. While the apple donuts cool, melt the butter in one bowl and whisk the cinnamon and sugar until well combined. Dip both sides of the cooled donut into the melted butter. Quickly roll the entire baked donut into the cinnamon sugar mixture. Place each apple cinnamon donut on the cooling rack. Repeat until all the donuts are coated in the sweet and crunchy coating and enjoy. ½ cup (113 g) unsalted butter, melted, 1 cup (200 g) granulated sugar, 2 teaspoons ground cinnamon