Preheat oven to 350°F. Grease and flour a Bundt pan.
In a small bowl, mix sliced apples with cinnamon and 5 tablespoons sugar. Set aside.
In a large bowl, mix flour, 2 cups sugar, baking powder, and salt.
Add oil, eggs, orange juice, and vanilla to the flour mixture and beat until smooth.
Pour half of the batter into the pan. Add half of the apples. Pour in the rest of the batter, then the remaining apples on top.
Bake for about 1 hour and 30 minutes or until a toothpick comes out clean.
Let the cake cool completely in the pan before inverting onto a plate.