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High-Altitude Banana Rum Cake Recipe

Vespa's recipes have appeared in "Midwest Living" and "Taste of Home." She belongs to Cook's Recipe Testers for "Cook's Illustrated."

Read on for my recipe and tips for a high-altitude bundt cake!

Read on for my recipe and tips for a high-altitude bundt cake!

Foolproof Banana Rum High-Altitude Bundt Cake

I am no stranger to high-altitude baking. In Cusco, at an elevation of over 11,000 feet (3.400 meters), I tearfully watched many cakes rise and fall, explode, and even implode. I was almost ready to turn in my oven mitts. Six years after finally mastering the art of high-altitude baking, we moved to Peru's coast. My first thought was, "Great! I can't wait to bake at sea level again!"

And now here we are again, almost ten years later, living at high altitude. This time the altitude is a little more reasonable: just 9,000 feet—1.5 miles high—up there with Vale, Colorado, and Kurush, Russia. But why is baking at high altitudes such a challenge? Factor in a lower boiling point, low air pressure, and dry atmospheric conditions and you have a recipe for disaster, or at least an unpredictable outcome to your kitchen experiments.

So is baking at high altitude a hopeless proposition? Not if you're willing to do a little research, make adjustments to your recipes, and measure ingredients like a scientist! Keep records of measurements so you can repeat those that work for you.

What's so special about this banana rum cake? Bananas strengthen the cake structure, making the recipe practically foolproof. Since high-altitude baking tends to dry out cakes, bananas also add moisture while rum amps up the flavor. Finish it with a dusting of powdered sugar or a lightly flavored rum icing and you have the perfect high-elevation cake.

Serve banana rum cake with a mug of steaming coffee or a tall glass of cold milk. Either way, you'll have a perfect dessert or midday snack. Take the stress out of high-altitude baking and make this moist, flavor-packed cake today!

Tips

  • This recipe is for baking a cake at 9,000 feet. If you live at a different altitude, please check the chart at the end of this page for adjustments.
  • This cake has a lighter texture and a more tender crumb than banana bread.
  • Choose very ripe bananas for a moist, sweet bundt cake.
  • It's important to whip egg whites just until soft peaks form so as not to over-inflate the cake. The whites will look foamy when ready.
  • Carefully follow the mixer speeds indicated in the instructions section.
  • If you don't want to use the rum, substitute 1/2 cup of whole milk.
  • For this recipe, use a 10-cup bundt pan so the batter doesn't overflow while baking.
  • Be sure to thoroughly grease and flour the bundt pan so the cake doesn't stick.
  • Cool thoroughly before unmolding.
  • Wrap the cake while it's still slightly warm.
  • This cake is even better when served the next day.
  • Dust with powdered sugar or drizzle with a simple glaze before serving, or leave cake unadorned and serve it for breakfast with a cup of hot tea or coffee.

Cook Time

Prep timeCook timeReady inYields

20 min

1 hour

1 hour 20 min

1 bundt cake, serves 10 to 12

Ingredients

  • 6 ounces (1 1/2 sticks) salted butter, softened
  • 1 cup white sugar
  • 1/2 cup brown sugar
  • 3 large eggs, separated
  • 3 cups unbleached flour
  • 1/2 teaspoon salt
  • 1 1/2 teaspoons baking powder
  • 1 cup whole milk
  • 1/2 cup dark rum*
  • 1 teaspoon vanilla extract
  • 4 very ripe bananas, thoroughly mashed

* If you prefer not to use rum, substitute 1/2 cup whole milk or try pineapple juice for a tropical flavor.

Instructions

  1. Thoroughly grease and flour a 10-cup bundt cake pan. Preheat oven to 350°F (180°C).
  2. In a large mixing bowl, beat softened butter and sugars with a hand mixer or stand mixer until light and fluffy. Use high speed. Add vanilla extract and mashed bananas, blending until well combined.
  3. Add egg yolks, one at a time.
  4. Combine flour, salt, and baking powder in a medium mixing bowl.
  5. Measure milk and rum in a large mixing cup.
  6. Reduce mixer speed to low. In 3 separate additions alternate adding dry ingredients and wet to the butter/sugar mixture, starting and ending with the flour mixture, until just incorporated.
  7. Beat egg whites just until foamy. It's important not to beat whites until stiff at high altitude to avoid over-inflating and collapsing the cake.
  8. Using a rubber spatula, carefully fold egg whites into the cake batter.
  9. Pour batter into the prepared bundt pan.
  10. Bake at 350°F for 50 to 60 minutes, or until a tester toothpick comes out clean.
  11. Cool cake for at least 30 minutes, until cool enough to easily unmold.
  12. Wrap the cake in plastic wrap while still slightly warm.
  13. Eat cake immediately or, if you prefer, wrap and eat the following day. Enjoy!

Challenges of High-Altitude Baking

If there's anything we've learned about high-altitude baking after all these years of living in the Andes mountains, it's that you must measure like a scientist and take plenty of notes. Attach a sticky paper to your recipe and jot down the measurements you use each time. Even though high-altitude baking is a science, unfortunately, it also takes experimentation to create the perfect recipe for your location.

Why?

Daily barometric pressure and humidity vary and that affects the outcome of your baking. But once you've come up with a general recipe that works for your location, you will turn out beautiful cakes time after time.

Adjust just two or three ingredients on your first attempt. We recommend starting with less sugar, fat, and leavening. Fat includes either butter, shortening, or oil. Those adjustments often work for us. If not, we increase the liquid and flour on the next attempt. Liquid can include water, milk, or even eggs. (One large egg is equivalent to 3 tablespoons, so at 7,000 feet or higher you can add one whole egg to the cake. At slightly lower altitudes, try adding one egg yolk.) All liquids add strength to the structure of your cake.

Most recipes need no adjustments up to 3,000 feet but then the need for adjustments increases exponentially as altitude increases. See the following chart for more information. Most importantly relax, take your time and have fun as you perfect your high-altitude baking technique.

How to Make High-Altitude Adjustments to Sea Level Recipes

AltitudeIncrease Flour By:Increase Liquid By:Decrease Fat or Sugar By:Decrease Baking Powder By:

4,000 feet

1/2 Tablespoon

1/2 Tablespoon

1/2 Tablespoon

1/4 of original quantity

5,000 feet

1 Tablespoon

1 Tablespoon

1 Tablespoon

1/4 of original quantity

6,000 feet

2 Tablespoons

2 Tablespoons

1 1/2 Tablespoons

1/4 of original quantity

7,000 feet

3 Tablespoons

3 Tablespoons

2 Tablespoons

half of original quantity

8,000 feet

4 Tablespoons

4 Tablespoons

2 1/2 Tablespoons

half of original quantity

9,000 feet

5 Tablespoons

5 Tablespoons

3 Tablespoons

half of original quantity

10,000 feet

6 Tablespoons

6 Tablespoons

3 1/2 Tablespoons

half of original quantity

Favorite High-Altitude Cake