For a delicious twist on a breakfast style coffee cake, top a moist and tender chocolate cake with buttery walnut streusel crumbs. This high altitude chocolate crumb cake is simple to make, and is the perfect excuse to eat cake for breakfast!
You might also love these high altitude crumb cake recipes for toasted hazelnut coffee cake, pumpkin crumb coffee cake, and carrot crumb coffee cake.
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Why You’ll Love This Recipe
Simple and Easy. You won’t need a mixer or any special equipment to make today’s chocolate crumb cake.
Soft and Moist for Days. You can enjoy this cake warm from the oven and save the leftovers for another day.
High Altitude Tested. I develop all the recipes on my site for Denver’s altitude of 5,280 feet. If you’re at a lower or higher elevation, please see my FAQs for guidance on adjusting recipes for your altitude.
See the recipe card at the end of the post for the full ingredients list and instructions.
Ingredients
Cake
- Flour. All purpose flour gives the cake batter structure and strength.
- Granulated Sugar. Adds sweetness and moisture.
- Cocoa Powder. Use unsweetened Dutch processed cocoa powder for a rich, chocolatey flavor.
- Espresso Powder. Enhances the flavor of the chocolate and adds a hint of coffee.
- Baking Soda + Baking Powder. Leavening agents, so the cake rises as it bakes.
- Salt. Balances the sweetness and enhances flavors.
- Eggs. Add moisture, richness and strength.
- Milk + Sour Cream. The fat in whole milk and sour cream makes the cake tender, moist and flavorful.
- Oil. Moisture.
- Vanilla Extract. Flavor.
Crumble
- Flour. Gives the crumble topping structure.
- Sugar. A combination of granulated sugar and brown sugar adds sweetness.
- Cinnamon. A little spice complements the flavor of the chocolate cake and the walnuts.
- Salt. Balances the sweetness and enhances flavors.
- Walnuts. Adds a nutty crunch, although they are optional.
- Butter. Binds the crumble mixture together.
Instructions
Cake
- Preheat the oven to 350 F, and position a rack in the center of the oven. Line a 9-inch square baking pan with parchment paper, or spray the pan with non-stick baking spray.
- In a bowl, sift together the flour, sugar, cocoa powder, espresso powder, baking soda, baking powder and salt.
- Separately, whisk together the eggs, milk, sour cream, oil and vanilla.
- Add the dry ingredients to the wet, and whisk just until combined. Pour the batter into the prepared pan.
Crumble
- In a bowl, combine the flour, sugar, brown sugar, cinnamon, salt and walnuts. Add the melted butter, and stir together until moistened and crumbly.
- Sprinkle the crumble mixture evenly over the chocolate cake batter.
- Bake the cake for about 40-45 minutes, until a cake tester or toothpick inserted in the center of the cake comes out clean, or with moist crumbs clinging to it.
- Set the pan on a cooling rack, and let cool for at least 45 minutes. Enjoy the cake warm, or at room temperature.
Be sure to read all of my BAKING FAQs where I discuss ingredients, substitutions and common baking questions, so that you can be successful in your own baking!
Frequently Asked Questions
Can I make the crumble topping without the walnuts?
Yes, you can use a different nut, like pecans or almonds, or just leave the nuts out completely.
Can I add cocoa powder to the crumble topping to make a chocolate crumble?
I’ve tried this before, but honestly, I didn’t love the results.
How should I store leftover cake?
Store leftover chocolate crumb cake in an airtight container at room temperature for up to 5 days. You can re-warm individual pieces in the microwave at 50% power for 30-40 seconds, for a soft, just-baked texture.
Can this recipe be doubled?
Yes, you can double the recipe and bake it in a 9×13 inch baking pan, for about the same amount of time or a few minutes longer.
You Might Also Like
Please check out my Amazon Shop for a curated collection of some of my favorite cake pans from trusted brands, baking tools, ingredients, pretty things and fashion finds. I recommend products that I buy and use every day!
Did you love today’s recipe? Please rate the recipe and let me know in the comments what you thought! Also, be sure to follow Curly Girl Kitchen on Instagram, and tag me when you try one of my recipes so I can see all your delicious creations!
High Altitude Chocolate Crumb Cake
All recipes on Curly Girl Kitchen are developed for high altitude at 5,280 feet. See FAQs for adjusting to higher or lower elevations.
Equipment
Ingredients
Cake
- 1 cup all-purpose flour, fluffed, spooned and leveled
- ¾ cup + 2 tbsp granulated sugar
- 6 tbsp unsweetened Dutch processed cocoa powder
- 1 tbsp instant espresso powder or instant coffee
- ½ tsp baking soda
- ¼ tsp baking powder
- ½ tsp coarse Kosher salt (if using table salt, use half the amount)
- 2 large eggs
- ½ cup whole milk
- ½ cup full fat sour cream
- ½ cup vegetable oil
- 1 ½ tsp vanilla extract
Crumble
- 1 ½ cups all-purpose flour fluffed, spooned and leveled
- â…“ cup granulated sugar
- â…“ cup light brown sugar, lightly packed
- ½ tsp ground cinnamon
- ¼ tsp coarse Kosher salt (if using table salt, use half the amount)
- ¼ cup finely chopped walnuts or pecans (optional)
- ½ cup unsalted butter, melted
Instructions
Cake
- Preheat the oven to 350 F, and position a rack in the center of the oven. Line a 9-inch square baking pan with parchment paper, or spray the pan with non-stick baking spray.
- In a bowl, sift together the flour, sugar, cocoa powder, espresso powder, baking soda, baking powder and salt.
- Separately, whisk together the eggs, milk, sour cream, oil and vanilla.
- Add the dry ingredients to the wet, and whisk just until combined. Pour the batter into the prepared pan.
Crumble
- In a bowl, combine the flour, sugar, brown sugar, cinnamon, salt and walnuts. Add the melted butter, and stir together until moistened and crumbly.
- Sprinkle the crumble mixture evenly over the chocolate cake batter.
- Bake the cake for about 40-45 minutes, until a cake tester or toothpick inserted in the center of the cake comes out clean, or with moist crumbs clinging to it.
- Set the pan on a cooling rack, and let cool for at least 45 minutes. Enjoy the cake warm, or at room temperature.
Does the cake need to be prebaked a bit before you put the crumble on top? I added the crumble immediately and it then sank completely into the cake while baking. Taste wise still kind of okay, but nothing to serve people if you know what I mean.
The cake does not need to be prebaked, it should be assembled exactly as stated in the instructions. If your crumble sank into the batter, then perhaps your measurements were off somewhere, maybe with too much liquid in the cake or something like that? Also, if you’re at a different altitude than me, then you will need to refer to my FAQs to make adjustments for your altitude: https://curlygirlkitchen.com/baking-faqs/