Preheat the oven to 350F and generously grease a 10 cup or standard size bundt pan, getting into every groove. I use my own cake goop recipe and the cake releases every time.
In a medium bowl, whisk together the flour, cinnamon, nutmeg, cardamom, allspice, salt, baking powder and baking soda. Set aside.
3 cup AP flour, 2 tsp cinnamon, 1/4 tsp nutmeg, 1/2 tsp cardamom, 1/4 tsp all spice, 1/2 tsp salt, 2 tsp baking powder, 1/2 tsp baking soda
In a large measuring cup, stir the apple cider and applesauce together. Set aside. No reducing needed, the applesauce is what carries the moisture here.
1 cup apple cider, 3/4 cup unsweetened apple sauce
In a large bowl, beat the oil with the brown sugar and granulated sugar until the mixture loosens and looks glossy rather than sandy.
2/3 cup oil, 2/3 cup dark brown sugar, 1 cup granulated sugar
Add the eggs one at a time, beating well after each, then beat in the vanilla until the mixture is smooth and slightly paler.
2 tsp vanilla extract, 2 large eggs
Alternate adding the dry ingredients and the cider mixture into the sugar mixture, beginning and ending with the flour. Stop as soon as the last streaks disappear. Do not overmix.
Pour the batter into the prepared pan and smooth the top. Bake 40 to 50 minutes, until a wooden skewer inserted in the thickest part comes out clean.
Cool in the pan 10 minutes, then invert onto a cooling rack set over a baking sheet. While the cake is still warm but no longer hot, brush every surface with melted butter and coat generously in the cinnamon sugar. Let the crust set a few minutes before slicing.
5 tbsp butter, 3/4 cup granulated sugar, 1 tbsp cinnamon
Notes
Mini bundt conversion: this batter makes about 12 mini bundts. Fill each cavity three quarters full and bake 18 to 22 minutes. Coat while warm, same as the full size cake.No cider reduction needed. The applesauce does the moisture work, so full strength cider goes straight in. If you prefer a stronger apple flavor you can reduce yours first, just still measure out the full 1 cup.