High Altitude Chai Pumpkin Sheet Cake with Coffee Buttercream

Incredibly moist, high altitude chai pumpkin sheet cake full of warm spices and brown butter, with fluffy coffee buttercream, decorated with cocoa powder stencils. This pretty fall themed cake is easy to decorate with stencils, which you can customize for any special occasion or holiday, from Halloween to Thanksgiving.

You might also love these high altitude recipes for pumpkin chocolate chip loaf bread, pumpkin layer cake with cream cheese buttercream, and pumpkin crumb cake muffins.

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Why You’ll Love This Recipe

Versatile Decorating Options. I love to show that a sheet cake doesn’t have to look boring, and can look just as pretty and impressive as a tall layer cake. While debating various autumn and fall cake decorating ideas, I came across these cute fall themed stencils on Amazon, and my idea for today’s cake was born. And with so many fun stencils to choose from, you can customize this cake for Thanksgiving, Halloween, or a fall birthday party.

Cozy Chai Flavors. Chai spice mixes typically include cinnamon, ginger, cardamom, cloves, nutmeg, allspice, and sometimes star anise. There’s so much warmth and coziness in these spices, and they beautifully complement the flavor of the pumpkin, brown sugar and coffee. If you’re a fan of dirty chai lattes or pumpkin spice lattes, then you’ll love the flavors of this chai pumpkin sheet cake.

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

• Brown Butter. Besides flavor, the brown butter adds moisture and richness to the cake.
• Pumpkin. You’ll need plain canned pumpkin, not pumpkin pie filling.
• Sugar. Both brown sugar and granulated sugar add sweetness and moisture.
• Eggs. The eggs add structure and richness to the cake.
• Buttermilk. If you don’t have buttermilk, you can replace it with whole milk and a teaspoon of apple cider vinegar. The acidity makes a soft, tender cake.
• Vanilla Extract. Flavor.
• Flour. Plain all purpose flour gives the cake structure and strength.
• Baking Soda. The baking soda reacts with the acid in the buttermilk and pumpkin to leaven the cake.
• Salt + Spices. So, you’ll never see “pumpkin pie spice” listed as an ingredient in my pumpkin recipes. If you have it, though, use it! But I like to add my spices separately. Salt, cinnamon, ginger, cardamom, allspice, cloves and nutmeg give this cake amazing flavor that perfectly complements the pumpkin.

Buttercream

• Butter. I always use unsalted butter, then add a pinch of salt.
• Powdered Sugar. Sweetens and thickens the buttercream.
• Meringue Powder. Adds stability and improves the texture.
• Salt. Balances the sweetness.
• Cream or Milk + Instant Espresso Powder. By dissolving instant espresso powder in liquid first, before adding it to the buttercream, you’ll get a stronger coffee flavor.
• Vanilla Extract. Flavor.
• Cocoa Powder. For stenciling.

Instructions

Cake

• Preheat the oven to 350 F, and position a rack in the center of the oven. Line a 9×13 inch baking pan with parchment paper, and lightly spray the paper with non-stick baking spray.
• In a saucepan over medium heat, melt the butter. Continue to cook the butter, swirling the pan occasionally, for about 10 minutes, until the water has evaporated, and the butter is forming nutty, fragrant golden brown solids at the bottom of the pan. Remove the pan from the heat and let the butter cool for 10 minutes.

• In a large bowl, whisk together the browned butter, pumpkin, brown sugar, granulated sugar, eggs, buttermilk and vanilla.
• In a separate bowl, sift together the flour, baking soda, salt and spices. Add the dry ingredients to the wet, and whisk for about 15-30 seconds until smooth.

• Pour the batter into the prepared pan. Bake the cake for about 28-30 minutes, until a cake tester or toothpick comes out clean.
• Set the pan on a wire cooling rack, and cool completely before frosting.

Buttercream

• In the bowl of your stand mixer fitted with the paddle attachment, beat the butter for one minute.
• With the mixer on low, add the powdered sugar, meringue powder and salt, mixing until combined but clumpy.
• In a small bowl, whisk together the cream, espresso powder and vanilla until the espresso powder is dissolved. Add the espresso mixture to the buttercream.
• Increase speed to medium, and whip for 4-5 minutes, scraping the bowl occasionally, until light and fluffy. Turn the speed down to “stir” and mix for 1 minute.

Decorating

• Turn the cooled cake out onto a serving board. Frost the cake all over with the buttercream; you should have at least 1 cup of buttercream leftover. If decorating the cake with stencils, smooth the top of the cake the best you can, keeping it level all over.
• Carefully arrange the stencils on top of the cake, then use a small sifter to lightly dust the cocoa powder over the stencils. Carefully remove the stencils.
• Fit a piping bag with tip #18, and fill with buttercream. Pipe shell borders in between the stencils and around the edge of the cake.

Be sure to read all of my BAKING FAQs where I discuss ingredients, substitutions and common questions with cake making, so that you can be successful in your own baking! I also suggest reading these comprehensive posts on making Perfect American Buttercream, How to Stack, Fill, Crumb Coat and Frost Layer Cakes and How to Use Piping Bags.

Frequently Asked Questions

Where did you get the stencils?

I used these fall themed stencils on Amazon. Each stencil measures 3×3 inches, so it worked out well to be able to arrange 12 of them on top of a 9×13 cake, so that each square of pumpkin sheet cake has its own stenciled design. I also love the idea of using one big pumpkin stencil, or Halloween stencils.

Does the cocoa powder stay put on top of the cake?

The cocoa powder stencils stayed put extremely well. But the cocoa powder will start to absorb moisture as the cake sits, causing it to turn darker. If this bothers you, you can wait to decorate the cake until you’re ready to serve it.

Will this pumpkin sheet cake recipe work as a layer cake, too?

Yes, absolutely. You can bake the cake batter in three 8-inch cake pans for a layer cake.

How should I store the cake?

Store leftover cake in an airtight container at room temperature for up to 3 days.

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