Preheat the oven to 350 degrees. Line a 9 x 13 baking pan with parchment paper, leaving some hang out the sides if you will be lifting the whole cake from the pan to serve. If serving directly from the pan, skip this step and lightly spray the pan with cooking spray.
Whisk together flour, baking powder, salt and cinnamon in a bowl.
In another larger bowl, whisk together oil, brown and white sugar, eggs and vanilla until combined.
Add the dry ingredients to the wet ingredients and stir until just combined. Stir in the chopped apples.
Pour into the prepared pan, smoothing the top. Bake for 30-35 minutes or until a cake tester inserted in the middle comes out clean.
Let the cake cool in the pan completely before attempting to lift it out of the pan for serving. Once cooled, frost the cake with the cream cheese frosting.