Coffee Walnut Cake with Coffee Buttercream Recipe

If you love the perfect combo of rich coffee flavor and crunchy walnuts, then you’re in for a treat with this Coffee Walnut Cake with Coffee Buttercream Recipe. I absolutely love how this turns out every single time—it’s moist, fluffy, and that buttercream? Oh, it’s just heavenly. Whether it’s for a cozy afternoon treat or impressing friends at your next brunch, this cake truly steals the show. Stick around because I’ll walk you through every step to make sure your coffee walnut cake comes out flawless and totally delicious!

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Ingredients You’ll Need

Every ingredient in this Coffee Walnut Cake with Coffee Buttercream Recipe is chosen to build that perfect harmony of taste and texture. Using instant coffee gives a punchy coffee flavor without bitterness, while brown sugar adds moistness and depth. Fresh walnuts bring in the satisfying crunch and nutty aroma, making every forkful a little celebration.

• Instant coffee: Use good-quality instant coffee for maximum flavor – it dissolves quickly and won’t leave grit.
• Boiling water: Helps dissolve the coffee, ensuring an even taste throughout your cake and buttercream.
• Butter (softened): Soft butter cream-whips better, giving that fluffy texture in both cake and buttercream.
• Brown sugar: Adds moisture and richness; I prefer dark brown sugar for deeper flavor but light works too.
• Eggs: Bring structure and richness—take them to room temperature for better mixing.
• Flour: Plain (all-purpose) flour works best here — sift it to avoid lumps and to keep the batter light.
• Baking powder: Makes sure your cake rises evenly and stays tender.
• Finely chopped walnuts: Toast them lightly if you want an extra nutty aroma before mixing in.
• Icing sugar: For that silky smooth buttercream; I like to sift it to avoid clumps.

Variations

I’ve played around with this Coffee Walnut Cake with Coffee Buttercream Recipe quite a bit, and it’s fun to personalize it depending on what you have on hand or your taste buds’ mood. Don’t be afraid to experiment—you might discover a favorite twist!

• Walnuts to Pecans or Hazelnuts: I swapped walnuts for toasted hazelnuts once and loved the slightly sweeter, earthier flavor contrast with the coffee.
• Espresso Powder instead of Instant Coffee: For a more intense coffee flavor, I sometimes boost the coffee taste with espresso powder, but adjust the amount so it’s not overpowering.
• Gluten-Free Version: I’ve tried a combination of almond and gluten-free flour—while the texture changes a bit, you still get the lovely moist crumb.
• Adding a Splash of Whiskey or Coffee Liqueur: Doesn’t everyone love a grown-up twist? A teaspoon or two folded into the buttercream took it from delicious to downright addictive.

How to Make Coffee Walnut Cake with Coffee Buttercream Recipe

Step 1: Prep and Brew Your Coffee

The coffee is the star, so get this right. Mix your instant coffee with boiling water to dissolve it completely—this ensures you get even distribution of coffee flavor in both the cake and the buttercream. Let it cool while you prep other ingredients so it doesn’t scramble the eggs when added.

Step 2: Cream Butter and Sugar Until Fluffy

This is my favorite part because that pale, fluffy butter and sugar mixture is the base of your cake’s tenderness. Using a stand mixer or hand mixer, beat softened butter with brown sugar until it looks lighter in color and airy—usually about 3-5 minutes. Don’t rush it here; it makes a big difference to the crumb.

Step 3: Add Eggs One at a Time

Add eggs one by one, beating well after each addition to keep the mix smooth and prevent curdling. I used to worry about this step, but taking your time here ensures your batter stays silky and stable.

Step 4: Combine Coffee and Fold in Dry Ingredients

Pour the cooled coffee mix in and stir just until combined. Then sift your flour and baking powder directly over the bowl and gently fold these into the batter along with the chopped walnuts. Overmixing can make the cake tough, so be gentle and patient here.

Step 5: Bake Your Cake Evenly

Divide the batter evenly between two lined 18cm cake tins, spread to the edges with a spatula, and pop them in the oven’s center rack. Baking at 160°C fan bake (or 180°C conventional) for 25-30 minutes usually works perfectly. A skewer inserted in the middle should come out clean when done. I check a couple minutes before time’s up—I’ve learned cakes can go from just right to dry surprisingly fast!

Step 6: Make the Coffee Buttercream

While the cakes cool, make the icing. Like before, dissolve coffee in boiling water and let it cool. Beat softened butter and brown sugar until fluffy, then add coffee and sifted icing sugar. Beat for about 3-5 minutes until creamy and light. This step builds the luscious texture that makes the cake sing.

Step 7: Assemble and Decorate

If your cakes have domed, slice off the top of one for a flatter layering surface. Place that cake layer cut side down on a plate, spread half the coffee buttercream evenly to the edges. Top with the second cake layer, then cover the top with the rest of the frosting. I sprinkle extra chopped walnuts on the very top for crunch and visual appeal—always a crowd-pleaser.

How to Serve Coffee Walnut Cake with Coffee Buttercream Recipe

Garnishes

I love to keep it simple with extra chopped walnuts sprinkled on top—their crunch makes each slice so satisfying. Sometimes I add a few whole walnut halves as a rustic decoration or even dust a tiny bit of cocoa powder for depth. Fresh mint leaves can add a surprising fresh twist if you’re feeling fancy.

Side Dishes

This coffee walnut cake pairs beautifully with a hot cup of black coffee or a creamy latte for a true coffee lover’s dream. If you want to serve it more like dessert, a simple scoop of vanilla ice cream or a dollop of lightly whipped cream complements the cake’s richness perfectly.

Creative Ways to Present

For birthdays or special occasions, I’ve tried layering the cake with coffee-soaked ladyfingers for a tiramisu-inspired hybrid—that was a hit! Another fun idea is to pipe the buttercream decoratively with a star tip and add chocolate-covered espresso beans on top for that extra wow factor.

Make Ahead and Storage

Storing Leftovers

I usually keep this cake covered in an airtight container in the fridge—it stays fresh for up to 4 days. If you forget to refrigerate, you might notice the buttercream softens a bit at room temp, but it’s still delicious (just a bit messier to slice!).

Freezing

Freezing this cake is totally doable. I recommend freezing uniced cake layers wrapped tightly in plastic wrap and foil. When ready, thaw overnight in the fridge and then ice as usual. The buttercream doesn’t freeze well, so frosting fresh ensures the best texture.

Reheating

If you’ve refrigerated slices, I like to let them sit at room temperature for 20-30 minutes before serving—the buttercream softens up nicely this way. Reheating in a microwave for a few seconds can revive the cake’s warmth but watch closely to avoid melting the buttercream too much.

FAQs

Final Thoughts

This Coffee Walnut Cake with Coffee Buttercream Recipe has truly become one of my go-to celebratory cakes for a reason. It’s rich without being heavy, cozy with an energizing kick, and always a conversation starter when I serve it to friends and family. If you give it a try, I’m confident you’ll be just as hooked as I am! Plus, the hands-on process makes the final slice taste even sweeter. So grab your mixing bowls and coffee, and let’s bake this lovely cake together.

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