Ingredients
For the Cake:
1 box yellow cake mix
1 cup sour cream
4 large eggs
½ cup vegetable oil
For the Cinnamon Streusel:
1 cup brown sugar packed
1 tablespoon ground cinnamon
½ cup chopped pecans optional
For the Glaze:
1 cup powdered sugar
2 tablespoons milk
½ teaspoon vanilla extract
Instructions
Preheat to 350°F (175°C). Grease a 9×13-inch baking dish with nonstick spray or butter.
In a large bowl, mix yellow cake mix, sour cream, eggs, and vegetable oil until smooth and creamy. Use a hand mixer or whisk.
In a medium bowl, stir together brown sugar, ground cinnamon, and chopped pecans if using.
Spread half the batter into the dish. Sprinkle half the streusel on top. Repeat with remaining batter and streusel.
Bake for 35–40 minutes, until a toothpick inserted in the center comes out clean or with a few moist crumbs.
Let the cake cool in the pan for 20 minutes before glazing.
Whisk powdered sugar, milk, and vanilla extract in a small bowl until smooth and pourable. Adjust milk if needed.
Drizzle glaze over the slightly warm cake, letting it seep into the crevices.
