Instructions 

Step 1: Preheat & Prepare the Baking Dish

• Preheat your oven to 350°F (175°C).
• Grease a 9×13-inch baking dish with nonstick spray or butter.

Step 2: Make the Cake Batter

• In a large mixing bowl, combine the strawberry cake mix, vegetable oil, eggs, sour cream, milk, and vanilla extract.
• Mix with an electric mixer or whisk until the batter is smooth and creamy.

Step 3: Create the Cinnamon-Sugar Swirl

• In a small bowl, mix together the brown sugar and cinnamon.

Step 4: Layer the Cake

• Pour half of the cake batter into the prepared baking dish.
• Sprinkle the brown sugar-cinnamon mixture evenly over the batter.
• Pour the remaining batter on top and spread it evenly with a spatula.