Place the apple cider in a small saucepan over medium heat. Bring to a boil then reduce to a simmer and reduce the liquid by half. You will need 1 cup of reduced apple cider. Set aside to cool to room temperature.
Preheat oven to 350°F. Grease a 10 or 12 cup bundt pan. (I use cooking spray with flour in it to grease my bundt pans). I used a 12 cup bundt pan and had room to spare after it was fully baked.
In a large bowl whisk the flours, baking powder, baking soda, 1 1/2 tsp cinnamon, apple pie spice and salt.
In another bowl whisk 1 ½ cups granulated sugar, brown sugar, the reduced apple cider, oil, applesauce, vanilla, and eggs.
Add the wet ingredients to the dry ingredients and whisk to combine. Transfer the batter to the prepared bundt pan.
Bake for 45-50 minutes or until a toothpick inserted in the center comes out clean with a few moist crumbs on it. Transfer to a wire rack set over a rimmed baking sheet and let cool for 15 minutes.
While the cake is cooling in the pan, mix the remaining ¼ cup of sugar and ½ tsp cinnamon in a small bowl.
Invert the warm bundt cake onto the wire rack. Brush the cake with the melted butter then sprinkle the cake with the cinnamon sugar mixture. Let the cake finish cooling completely before slicing and serving.
Store the cake covered, at room temperature for 2 days.
Notes
You can grease a bundt pan with room temperature butter then dust it with flour, use shortening and flour, or spray liberally with a cooking spray containing flour.To make your own apple cider, place apple juice on the stove and add about 1/8 tsp of nutmeg, 1/8 tsp ground cloves, 1/2 tsp cinnamon, and 1 tsp all spice to the 2 cups of apple juice. (Optional, add 1-2 tablespoons of brown sugar to sweeten it). Simmer until reduced by half.