Preheat oven to 350ºF. Grease and flour a 10" tube or 12 cup Bundt pan.
In a mixing bowl, combine the cinnamon and sugar and add apple slices. Toss to coat. Set aside.
In a large mixing bowl, sift together the flour, baking powder, and salt, then add sugar, oil, eggs, juice, and vanilla and beat until smooth. Batter will be very stiff.
Spoon a third of the batter into the bottom of the pan. The batter will be thick so once you spoon it in, give it a slight “shimmy” to create an even layer. Arrange half the sliced apples on top, then add another third of the batter, the remaining apples, and top with the last third of the batter. Use your best rubber spatula to get all the good batter from the bowl so none goes to waste! Apples won’t be completely covered.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 1 hour 15 minutes. Cool in the pan for 20 minutes before inverting onto a serving platter. Then let it cool completely.
You can top the cake with a simple powdered sugar-and-orange juice glaze, a dusting of powdered sugar, or serve it as-is! Slice and enjoy!
