Combine 1 box yellow cake mix, 4 eggs, 1 cup sour cream, and ¾ cup oil (mixture may be slightly lumpy). Set aside.
In a separate bowl, mix together 1 cup brown sugar and 2 teaspoons cinnamon for the swirl mixture, and set aside.
Prepare a 9"x13" baking dish with Non-stick cooking spray. Pour half of the cake batter into the baking dish, spreading the batter out evenly. Add half of the swirl mixture to the top, covering the entire layer of batter. Pour the remaining batter on top, and spread out until even. Top with the rest of the swirl mixture.
With a knife, swirl the batter together in a circular motion. Bake for 45 minutes, or until cake tests done with a toothpick.
To make the glaze, mix together 2 cups powdered sugar, 6 tablespoons milk, and 1 teaspoon vanilla extract until glaze is smooth and lump free.
Top cake immediately with glaze as soon as it comes out of the oven.
Let cool before serving.
Notes
Gluten-free version. You can easily make this gluten-free by using a GF cake mix.Bundt pan version. You can bake this honey bun cake recipe in a regular baking pan or a Bundt pan. The Bundt pan will result in a beautiful cake that really shows the cinnamon swirls in each slice.Bundt pan adjustments. You will need to adjust the baking time to your specific pan, so start at about 40 minutes at 325ºF and check for doneness with a toothpick or wooden skewer. When it comes out clean or with only the cinnamon swirl on the wood, the cake is done. Let it cool until the pan is cool enough to touch, then put a cake platter upside down on the Bundt pan. Invert the pan so that the cake settles on the platter, and remove the pan. Drizzle the honey bun cake immediately with the glaze. You may need to cut back on the amount of glaze you use for the Bundt pan version.