Position a rack in the center of the oven and preheat to 350°F (175°C). Grease a 10-inch tube pan thoroughly, dust with flour, and tap out the excess.
Peel, core, and thinly slice apples to about 1/8 inch. Toss with sugar and cinnamon in a medium bowl until every slice is coated; set aside.
In a large bowl, whisk together flour, sugar, baking powder, and salt until evenly distributed.
In a second large bowl, whisk eggs until smooth. Add canola oil, orange juice, and vanilla; whisk until uniform and slightly pale.
Pour wet mixture into dry ingredients and stir with a silicone spatula just until no dry flour remains. The batter will be very thick; do not overmix.
Spoon one-third of the batter into the prepared pan and spread evenly. Scatter half the apples over it, leaving pooled juice behind. Repeat layers, finishing with the final third of batter spread evenly on top.
Bake at 350°F (175°C) for 1 hour 20 minutes, until deep golden and a skewer inserted into the center comes out clean. Tent with foil if the top browns too quickly.
Cool in the pan on a wire rack for 20 minutes. Run a thin knife around edges and center tube, then lift or invert the cake out and cool completely on the rack. Dust with confectioners' sugar before serving.