Preheat oven to 350 degrees. Grease a tube or bundt pan. Peel, core, and chop apples into chunks Toss with cinnamon and sugar, and set aside.
Stir together sifted flour, baking powder, and salt in a large mixing bowl. In a separate bowl whisk together oil, orange juice, sugar, and vanilla. Mix wet ingredients into the dry ones, then add eggs, one at a time. Scrape down the bowl to ensure all ingredients are incorporated.
Pour half of the batter into prepared pan. Spread half of the apples over it. Pour the remaining batter over apples, and arrange the remaining apples on top. Bake for 1 1/2 hours, or until tester comes out clean.