Preheat oven to 350F and grease 9x13 glass casserole dish.

In a large bowl using a hand mixer or using a stand mixer, beat together butter and sugar until creamy. Mix in eggs and vanilla until well combined, then beat in sour cream.

In a medium sized bowl, whisk together flour, baking powder, baking soda, and salt.

Slowly add dry ingredients into wet ingredients, using the mixer. Take breaks and scrape down sides as needed. Once all combined, batter will be thick and fluffy, but do not over-mix.

In a small bowl, combine sugar and cinnamon to make the cinnamon sugar filling.

Add half of the batter to the bottom of the greased pan, and use an icing spatula or rubber spatula to spread throughout the pan. It will be thick so use short, whispy strokes to spread.

Sprinkle half of the cinnamon sugar mixture on top of the batter, and then sprinkle half of the chocolate chips over top.

Add the remaining cake batter to the top, and again, use short, whispy strokes to spread the batter.

Sprinkle the remaining cinnamon sugar mixture and chocolate chips to the top.

Bake for 45-55 minutes or until toothpick inserted in middle comes out clean. Once baked, take out of oven and let cool at least 30 minutes before cutting into slices.