Preheat oven to 350°F. Spray or grease 10″ tube pan or bundt cake pan.
Mix cinnamon and 2 tsp sugar in small bowl and set aside.
In separate medium bowl, combine flour, baking powder, and salt and set aside.
In separate large bowl, beat together eggs and remaining sugar. Then add oil and orange juice. Once mixed together well, add dry items from medium bowl.
Beat everything together until smooth. Add vanilla and whisk everything thoroughly.
Add half of batter to greased pan. Place half of sliced apples on top of batter in a pinwheel pattern. Sprinkle 1 tsp of cinnamon sugar mixture over apples.
Gently and evenly top with remaining batter and repeat steps with remaining apples and cinnamon sugar.
Bake for 1 hour. Insert and remove toothpick to see if cake is done – toothpick should be dry. If cake is not baked through, place in oven for another 10 minutes.
Once baked, cool of an hour apple-side up on a wire rack.