Preheat the oven to 325 degrees F (165 degrees C). Grease a 9x12-inch glass baking dish.

Mix together sugar, cocoa powder, and cinnamon in a small bowl; set topping aside.

Combine butter and cream cheese in a large bowl; beat with an electric mixer until smooth and creamy. Add sugar and mix until well blended. Mix in vanilla extract. Add eggs, one at a time, beating well after each addition. Sift in flour and baking powder and blend until thoroughly combined. Fold in chocolate chips.

Pour 1/2 of the batter into the prepared baking dish and sprinkle with 1/2 of the cinnamon topping. Spread remaining batter on top and sprinkle with remaining topping.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, 45 to 60 minutes. Cool on a wire rack for 5 minutes. Serve warm.