The recipe for this high altitude dark chocolate cake was adapted from my standard recipe for success in high altitude conditions. You’ll find it to be rich, chocolatey, and perfectly moist.
Recently, we took a trip to visit our friends in Colorado and they asked me to bake my peanut butter cup layer cake for them. You can read more about our trip and the baking experience here. Because they live at a higher altitude than I am used to, I did some research to make sure my cakes would turn out perfectly. I am by no means an expert on high altitude baking, but I thought I would share with you what I found.
In case you were wondering about the science behind it, I learned that the lower air pressure in high altitudes is potentially problematic in baking. It can cause liquids to evaporate faster, cause the cake to rise too quickly, or affect the cooking times negatively. These factors could all result in a cake that is too dry, overly dense, or sunken in the middle – not ideal! So I knew I definitely had to find some solutions.
Based on my research (including this very helpful blog), and some suggestions from friends who are more familiar with high altitude, I made the adjustments listed below to my standard chocolate cake recipe. Note that the recipe at the end of this post is already adjusted for a moderately high altitude of just over 5,000 feet (our friends live near Boulder, CO). You only need to make further adjustments if you’re baking at a significantly higher altitude.
After each note on the adjustments I made, I also included in parentheses the standard suggestions for about 5,000 feet in altitude. Note that I didn’t necessarily follow the recommended measurements to a tee. Knowing that the altitude in Boulder isn’t as severe as other areas, I didn’t want to overdo it, but the changes I did make were definitely sufficient. I was incredibly happy with how this cake turned out.
- In order to help give the cake more structure, I decreased the sugar by about 2 tablespoons (as it is usually recommended to decrease by 1-2 tablespoons per cup of sugar in the recipe).
- To prevent dryness, I added a little more liquid, about 3 tablespoons extra (it is usually recommended to add 2 tablespoons per cup of liquid in the recipe)
- To prevent rapid rising, I slightly decreased the leavening in the recipe, using 1/8 teaspoon less of baking powder (it is usually recommended to decrease leavening by 1/8 to 1/4 teaspoon per teaspoon of leavening in the recipe).
- Finally, I increased the oven temperature by 25 degrees Fahrenheit, to 375 degrees F (it is usually recommended to increase by 25 degrees F in high altitude), and adjusted the baking time accordingly.
- And in case you were wondering, I tested this cake in two 9-inch cake pans because that’s what our friends happened to have. You could certainly use different size pans, but the baking time would change as well.
Look how beautiful those layers are!! You can use this high altitude dark chocolate cake in my Peanut Butter Cup Layer Cake recipe, or any other recipe calling for a chocolate cake. Like this Triple Berry Nutella Cake for example!
High Altitude Dark Chocolate Cake
- 2 cups all-purpose flour
- 3/4 cups unsweetened cocoa powder, special dark
- 1 tablespoon instant espresso powder
- 3/4 teaspoon baking powder
- 1 1/2 teaspoon baking soda
- 1 teaspoon salt
- 3/4 cup + 2 tablespoons sugar
- 1 cup brown sugar
- 1 cup vegetable oil
- 2 large eggs, room temperature
- 2 teaspoons pure vanilla extract
- 1 cup buttermilk*, room temperature
- 3/4 cup + 2 tablespoons very hot water
Preheat oven to 375 degrees Fahrenheit and line the bottom of two 9-inch cake pans with parchment paper. Grease and flour the pans.
Whisk dry ingredients (flour, cocoa powder, espresso powder, baking powder, baking soda, and salt) together in a medium sized mixing bowl.
Beat oil and sugars together until well incorporated.
Add eggs one at a time, beating until incorporated after each addition.
Scrape down sides of bowl and add vanilla, mix until just combined.
Alternate adding 1/3 of the flour mixture and 1/2 of the buttermilk to the mixing bowl, starting and ending with the flour. You will have three additions of flour and two additions of buttermilk. Scrape down the sides as needed and mix until incorporated after each addition.
Add hot water and mix until just combined with a rubber spatula.
Distribute batter evenly among the two cake pans, then transfer to oven.
Bake at 375 degrees for 22-25 minutes, or until a toothpick inserted into the center of each cake comes out with only a few moist crumbs attached.
Let cakes cool in pan for about 15 minutes, then turn out onto a wire cooling rack and let cool completely.
Frost and decorate as desired.
*Make your own buttermilk by measuring out a scant one cup milk (2% or whole), then adding about 1 tablespoon of vinegar or lemon juice. Stir and let sit for 5 minutes before using.