Ingredients

• 1 package yellow cake mix , 15.25 ounce
• 1 cup buttermilk
• 4 eggs
• 0.75 cups vegetable oil
• 0.5 teaspoons baking soda
• 1 cup brown sugar
• 2 teaspoons ground cinnamon
• 3 cups confectioners' sugar
• 0.75 cups milk
• 1 teaspoon vanilla extract , Optional

Instructions

1. 1 Preheat the oven to 325 degrees F (165 degrees C). Grease a 9x13-inch cake pan.
2. 2 Whisk cake mix, buttermilk, eggs, vegetable oil, and baking soda together in a bowl until thoroughly combined. Pour into the prepared pan.
3. 3 Stir brown sugar and cinnamon together in another bowl; spoon onto cake batter in several places. Use the spoon to gently swirl cinnamon-sugar mixture into cake batter; do not overmix as you want to have streaks and ribbons showing.
4. 4 Bake cake in the preheated oven until a toothpick inserted into the center comes out clean, 30 to 35 minutes. Remove from the oven and punch holes all over the cake with a table knife.
5. 5 Whisk confectioners' sugar, milk, and vanilla together in a bowl to form a smooth, runny icing. Pour icing all over warm cake, allowing it to soak into the holes. Let cool before serving, about 30 minutes.

Nutrition per serving