In the medium bowl, combine the flour, sugar, baking powder and salt and stir with a whisk until well blended.
In the bowl of an electric mixer, mix together the oil, eggs, orange juice and vanilla. Add the flour mixture and mix just until smooth (do not over mix), scraping down the sides of the bowl as needed to ensure that all of the dry ingredients are incorporated.
Pour the batter into the prepared springform pan.
In a bowl, toss the sliced apples with the cinnamon-sugar mixture until well-coated.
Arrange the apples all the way around the edge of the cake so that the rounded side of the slices are standing up and the pointed end of each slice is pressed into the batter. Following the same method, make additional inner rows of apples (depending on the size of your apples, this could be one or two rows) until the entire top of the batter is filled in with apples.
Bake the cake for 1½ to 1¾ hours or until a skewer inserted into the center of the cake comes out dry. (The skewer might be slightly sticky from the apples, but there should be no wet batter on the skewer.)
Cool the cake on a wire rack for about 30 minutes, then release the cake from the springform (use a knife around the sides of the cake if necessary to loosen it from the pan).
Cool the cake completely and dust with confectioner’s sugar before serving.