Pre-Heat oven to 350° Grease a tube pan. Peel, core and chop apples into chunks. Toss with cinnamon and 5 tbs of sugar and set aside Sift together flour, baking powder and salt in a mixing bowl. In a separate bowl, whisk together oil, orange juice, sugar and vanilla. In a mixer, 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 the prepared pan. Spread half the apples over it. Pour remaining batter over the apples and arrange the remaining apples on the top. Bake for about 1 ½ hours or until tester comes out clean.