Preparation Steps

• Begin by preheating your oven to 350°F (175°C) and greasing a 9x13 inch baking dish. This will ensure your cake comes out perfectly.
• In a large mixing bowl, combine the flour, baking powder, and baking soda, giving it a good whisk to mix everything well.
• In another bowl, use an electric mixer to cream together the sugar and melted butter. Add the eggs, sour cream, and vanilla, mixing until smooth.
• Gradually add the dry ingredients to the wet mixture, stirring gently until just combined — be careful not to overmix!
• In a small bowl, mix the brown sugar with the cinnamon to create a delightful topping.
• Pour half of the batter into your prepared dish, then sprinkle half of the cinnamon sugar mixture on top. Repeat with the remaining batter and topping.
• Using a knife, gently swirl the batter to create a marbled effect.
• Bake for 40-45 minutes or until a toothpick inserted in the center comes out clean. Then allow it to cool briefly before serving.