Kahlua Cake With Mocha Buttercream

This pretty Kahlua Cake is infused with coffee liqueur & espresso, and adorned with billowy mocha buttercream ruffles.

I can hardly believe we’re into May already. And it’s finally starting to feel like spring! We’re about 2 months behind here… After a crazy winter with ridiculous amounts of snow (for the West Coast) and the fact that it’s been completely dismal since September, Vancouvervites are dying for some sunshine and warm temps. Finally, FINALLY, we’re looking at multiple sunny days in a row and t-shirt weather.

The cake I’m bringing you today, on this sunny Sunday, is one I’ve been wanting to make for a while. I’m actually surprised I haven’t made anything with Kahlua yet for the blog — it’s a staple around here, just like Baileys, and we all know I have my fair share of Baileys recipes. It was time to let another delicious liqueur shine with this Kahlua Cake!

For the cake layers, I used my favourite vanilla cake recipe, except I used Kahlua instead of vanilla. You can use any coffee liqueur you like though, or stick with vanilla in the cake batter since there’s Kahlua in both the coffee soak (don’t skip this!) and the mocha buttercream.

The Kahlua coffee soak is a must-do, in my opinion. Really you could skip it, but it’s so easy to make and adds both flavour and moisture to the cake. After preparing the soak, I poked a bunch of holes (using bamboo skewers) into the warm cakes and brushed the soak onto each layer.

Next time, I’d probably wait till the cakes are cooled and trim off a very thin layer of the top to remove the “crust”. Then I’d brush the soak onto each layer. I feel like this would do a better job of penetrating through the cake. No matter which option you choose, don’t be shy with brushing the soak on!

This Kahlua Cake is finished off with my very favourite mocha buttercream. Honestly, this stuff is like crack. You’ll be eating it with a spoon for sure, and you’ll be very grateful for the leftovers (if there are any).

I wanted to try something a bit different with the decorating technique this time and (surprise, surprise!) I’m not totally happy with the way it turned out. The ruffles aren’t exactly difficult to do, but the challenge comes in as you try to get the rows perfectly even while your hand is getting tired and the buttercream is getting super soft in the piping bag you’ve been clutching onto. As such, the ruffles are a bit messy in parts, especially near the bottom (I started at the top).

I still think it looks pretty even though it’s not perfect, and most importantly it tastes DELICIOUS. You really can’t go wrong with the coffee + chocolate combo in my opinion.

Now, to do the ruffles, I used a large piping bag fitted with a large petal tip (Wilton #125). I started at the top of the cake, making sure that the first set of ruffles would peek over the top. I placed the thicker end of the tip against the cake at a 45 degree angle and piped the ruffles up and down as I spun my turntable. I repeated the process with subsequest rows, making sure to always start in the same place so that the “seams” would all be together at the back of the cake. All cakes have a “back” amiright?

Piping the ruffles gets more difficult as you work your way down for the reasons I mentioned:

• Your hand is tired
• Your buttercream is soft
• The angle is more awkward

To try to combat the soft buttercream, you can use a smaller piping bag and just refill it more often. I am lazy and I find refilling a used piping bag to be one of the most annoying things in the world, so I try to pack as much as possible into a large piping bag. This is not the best thing to do, and I don’t recommend it, but again, I’m lazy. And my laziness has no doubt caused these imperfect ruffles! Oh well. It is what it is, and did I mention it tastes delicious??

If you are a coffee fan, you will love this Kahlua Cake!

Tips for this Kahlua Cake:

• You can make this cake without coffee liqueur if you prefer. Just substitute vanilla for Kahlua in each recipe.
• You can use vanilla in the cake batter instead of Kahlua if you prefer, since the soak and buttercream have Kahlua already. I did not find the flavour to be overly strong, though.
• I recommend trimming/levelling the tops of the cake layers before brushing the soak on to get rid of the crust and help the soak, well, soak into the cake.
• Be sure to use instant espresso powder (not granules) in the buttercream. Otherwise, dissolve the granules in 1 Tbsp hot water and let cool before adding to the frosting.
• I used a large petal tip (Wilton #125) to make the ruffles.
• If you’re a fan of boozy or coffee flavoured desserts, be sure to check out my Coffee & Baileys Cake, Mocha Chocolate Cake, and Baileys Cheesecake Cookie Cups!
• To help ensure your cake layers bake up nice and flat, see my Flat Top Cakes post.

5 from 6 votes

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Kahlua Cake with Mocha Buttercream

This pretty Kahlua Cake is infused with coffee liqueur & espresso, and adorned with billowy mocha buttercream ruffles.

Course Dessert

Type Cake

Prep Time 2 hours

Cook Time 35 minutes

Servings 12

830 kcal

Author Olivia

INGREDIENTS

Kahlua Soak:

• 1/2 cup water
• 1/2 cup granulated sugar
• 1 Tbsp espresso powder
• 1/4 cup Kahlua coffee liqueur

Cake:

• 2 1/4 cups all-purpose flour
• 2 tsp baking powder
• 3/4 tsp salt
• 3/4 cup unsalted butter room temperature
• 1 1/2 cup granulated sugar
• 3 large eggs room temperature
• 1 Tbsp Kahlua coffee liqueur
• 1 cup buttermilk room temperature

Mocha Buttercream:

• 5 large egg whites
• 1 1/2 cups granulated sugar
• 2 cups unsalted butter room temperature
• 3 Tbsp Kahlua coffee liqueur
• 1 1/2 Tbsp espresso powder not granules
• 5 oz good quality dark chocolate chopped, melted, cooled

US Customary - Metric

INSTRUCTIONS

Kahlua Soak:

1. Bring sugar, water, and espresso powder to a boil in a small pot over med-high heat. Simmer for 1min. Remove from heat and stir in Kahlua. Set aside to cool.

Cake:

1. Preheat oven to 350F. Grease and flour three 6" cake rounds and line with parchment.
   

2. In a medium bowl, whisk flour, baking powder, and salt until well combined. Set aside.

3. Using a stand mixer fitted with a paddle attachment, cream butter and sugar on med-high until pale and fluffy (approx 3mins). Reduce speed and add eggs one at a time fully incorporating after each addition. Add Kahlua. 

4. Alternate adding flour mixture and buttermilk, beginning and ending with flour (3 additions of flour and 2 of milk). Fully incorporating after each addition. 

5. Bake for 30-35mins or until a toothpick inserted into the center comes out mostly clean. 

6. Place cakes on wire rack to cool for 10mins then turn out onto wire rack. Poke holes into the cakes using a bamboo skewer and brush generously with Kahlua soak.

7. Allow cakes to cool completely. 

Mocha Buttercream:

1. Place egg whites and sugar into the bowl of a stand mixer, whisk until combined.*

2. Place bowl over a double boiler on the stove and whisk constantly until the mixture is no longer grainy to the touch (approx. 3mins).

3. Place bowl on your stand mixer and whisk on med-high until the meringue is stiff and cooled (the bowl is no longer warm to the touch (approx. 5-10mins)).

4. Switch to paddle attachment. Slowly add cubed butter and mix until smooth.**

5. Add cooled melted chocolate and espresso powder. Mix until combined. Slowly stream in Kahlua and whip until smooth.
   

Assembly:

1. Place one layer of cake on a cake stand or serving plate. Top with approximately 2/3 cup of buttercream. Repeat with remaining layers and crumb coat the cake. Chill for 20mins. 
   

2. Frost the top of the cake with approximately 2/3 cup of buttercream. Do a decorative swirl using a large offset spatula. Smooth any frosting that overhangs the sides.

3. Using a large petal tip, pipe ruffles around the cake in horizontal rows starting at the top.

4. Decorate with coffee beans if desired.

NOTES

* Ensure there is NO trace of egg yolks in your whites and that your mixer bowl and whisk is completely grease free or your meringue won't stiffen.

** The buttercream may look like it's curdled at some point. Keep mixing until it is completely smooth.

The nutritional information and metric conversions are calculated automatically. I cannot guarantee the accuracy of this data. If this important to you, please verify with your favourite nutrition calculator and/or metric conversion tool.