Of all the brownies we made at the bakery or I have ever eaten for that matter, Mocha Kahlua Brownies are my favorite. The brownie itself is of the fudgy variety with a deep, intense chocolate flavor highlighted with coffee undertones.
Mocha Kahlua Brownies couldn't be easier to make, sophisticated taste. The one thing that is important is to mix the batter on low so no air is incorporated.
The baked Mocha Kahlua Brownies often have a paper thin layer on top which is why I just turn them over so I have a perfectly smooth finish to frost. 
The frosting for these is absolutely addictive. I could be happy just eating it by the spoonful, preferably a large spoon.
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I have always cut these into squares and decorated them with a small rosette of dark ganache to contrast the light color of the frosting. The other way we cut these at the bakery was for petit fours in which case we cut them 6 across the nine inch side and 8 down for 48 petit fours. No one could resist these Mocha Kahlua Brownies and I'll bet they become one of your favorites also.
This blog for the Mocha Kahlua Brownies was originally published in 2010 for my first blog, The Ardent Cook, which is no longer active. I was just beginning then and as you can see, I have progressed as I went on. The Ardent Cook was my "practice blog". I always knew I wanted a pastry blog, but I wanted to work out all the quirks and establish my format before I launched Pastries Like a Pro. The Ardent Cook was a general blog and had a lot of wonderful (if I do say so myself) recipes on it.
Mocha Kahlua Brownies
6 tablespoons unsalted butter (90 grams or 3 ounces)
9 ounces semi sweet chocolate (255 grams)
5 eggs
2 ¼ cups sugar (450 grams or 16 ounces)
2 tablespoons warm water
2 tablespoons instant coffee
1 ¼ cup sifted all purpose flour (175 grams or 6 ounces)
Preheat oven to 350°F. Line the bottom of a 9x13 pan with parchment paper. Spray the paper with cooking spray. Set aside.
Place butter and chocolate in the top of a double boiler. Lacking a double boiler, place the ingredients in a bowl. Place the bowl over simmering water in a saucepan. 
Heat just to melt the butter and chocolate. 
Remove from over heat and stir or whisk until smooth. 
Alternately, this can be done in the microwave. I prefer to microwave chocolate at half power to prevent burning it. How long it takes depends upon the wattage of your microwave. I would start at 2 minutes at 50% power to start. Stir it, then add more time if necessary.
In the meantime, place the eggs and sugar in a mixer bowl and mix on low until well combined. 
Dissolve the coffee in the water and add to the sugar mixture, mixing on low until completely combined. 
Scrape the bottom of the bowl well and add the chocolate mixture. Mix well on low. 
Lastly, add the flour; mix well; scrape the sides and bottom of the bowl and mix again.
Pour batter into pan and smooth top. 
Rap the pan on the table once or twice to settle the air bubbles. Bake for 30 to 35 minutes until it is firm and a tester comes out just barely clean. Cool completely.
Mocha Kahlua Frosting
3 ounces semi sweet chocolate, melted and cooled (85 grams)
1 stick butter, room temperature (½ cup, 114 grams or 4 ounces)
1 ¼ cups sifted powdered sugar (170 grams or 6 ounces)
1 tablespoons Kahlua
¼ cup clear corn syrup
Melt chocolate; set aside to cool to room temperature.
Combine all the ingredients in a mixing bowl. 
Beat until very light in color and smooth. 
Remove brownie base from pan. Turn upside down. Spread frosting over the Mocha Kahlua Brownies. Refrigerate until firm. Divide into 15 pieces (3 across the narrow side and 5 down). Cut with a hot, dry knife. Pipe a rosette in the center of each if desired.
Cream Glaze (for rosettes), optional
¼ cup cream
2 ounces chocolate (60 grams)
Heat cream until steaming but not boiling. Submerge chocolate under cream. Wait a few minutes and gently whisk until smooth. Pipe rosettes with a small open star tip.
Note: These freeze beautifully for months if well wrapped. When thawing, it is important to place them in a container or covered with foil. That way the condensation goes to the top of the container or foil and not to the top of the brownies.
Yield: 15 brownies
Mari gold says
Where do you buy your Barry Callebaut chocolate?
hfletcher says
I get mine from a speciality wholesaler that services the restaurant. I would imagine you would have to go online.
Nikki says
Thank you for both recipes.
I am generally a "purist" when it comes to brownies, I am not fond of frosting on them. Most frosting that I have had on brownies seems to detract from the brownie itself and seems so heavy and overly sweet. This frosting looks much lighter so I might try it on the brownies but it WILL be used on a cake that I have in mind.
For brownies, I never use my mixer. Even on low the stand mixers can be so powerful that it is easy to over mix. And most important..an under baked brownie is better than an over baked one.
hfletcher says
Hi Nikki - My food philosophy is, in most cases, whatever works for you. However, at the bakery when we made multiple pans at once, there was no way to hand mix anything. I have never made these except with a mixer. Many of my recipes are broken down for those who enjoy baking at home. I generally don't change the technique or how it goes together but try to pass on what worked for us.
Many thanks for your comments.
Karin says
Dear Helen, what size of eggs (or weight) do you use? Here in Israel we have M, L and XL, and there is a huge weight difference between them.
Also, I am happy I found your blog. Baking is my hobby since I first helped my grandma as a little girl in Czechoslovakia. Note I like to learn the professional way, even if only via internet. I followed another blog, where I learned a lot of techniques, but frankly, I could not bake/eat anything from the recipes, as the usual US recipes are so overly sweet for me. Therefore I am happy to see your pastries at so balanced :)
Best regards and thank you!
Karin
hfletcher says
Hi Karin: The eggs used for any recipe on my blog as well as most, but not all, baking/pastry blogs are large. The large egg as specified in the U.S. is 2 ounces or 60 grams. However, the catch is they can actually be different sizes as long as the total weight of 12 eggs is 720 grams or 24 ounces. They are usually the same size in a carton though. The egg yolk weights 17 grams or .60 ounces. The white weighs 32 grams or approximately 1 ounce. The remainder of the weight is the shell.
At the bakery we weighed the yolks and whites as we worked with much higher volumes and a recipe could be thrown off if the number of whites or yolks were used as opposed to the weight.
My parents were from Yugoslavia and, while I like sweets, I have been known to reduce the sugar in recipes that I thought too sweet. This was particularly true of pies. I often found they were so sweet you couldn't taste the fruit. At the bakery we reduced the sugar and everyone loved them.
If you are new to the blog, check out the Baking Information section. I think you might find that interesting.
All best,
Helen
Karin says
Thank you Hellen, so sweet from you :)
I appreciate your dedication and how you find time and answer every comment. I will definitely read your suggestions. Best regards from Tel Aviv!
Amy says
Can these brownies be frozen?
hfletcher says
They can be Amy with great success. We sold them frozen so our clients could thaw what they wanted. One word about thawing. If you thaw them in a container, or just cover them with foil, the condensation will go to the top of the container or foil and not to the top of the brownie. This holds true for anything frozen, particularly frozen.
Thanks for bringing this to my attention so I can amend the blog.
Manisha says
Hi Helen
Just reading your recipe description is making my mouth water :) I have never been able to make good brownies. will try this one and I hope this will be success. What quality chocolate you have used in making these brownies - baking chocolate or coverture?? Will the quality of chocolate make difference in the taste and texture of the brownies?
Love
hfletcher says
Hi Manisha - I use a semisweet chocolate as I am not fond of bittersweet or unsweetened since I find they retain a bitter aftertaste I don't care for. The chocolate I used at the bakery was Guittard French Vanilla and was 58%. I used it for everything, baking, truffles, ganaches, etc. As a small bakery, I had not the room to store or the desire to use a bunch of different chocolates so sought out one that worked for everything chocolate. It must have worked as we were known for our chocolate desserts and candies. I currently use what used to be Callebaut and is now Barry Callebaut since they were bought out by Cocoa Barry. I use the semisweet calets (they look like chocolate chips but aren't) which are referred to as domestic or tulsa and are made in Canada. It is 52% and is a coverture chocolate.
You should use a good grade of chocolate but essentially any good grade from Guittard,Ghirardelli or like chocolate will be fine. It is a waste of money to use a 72% chocolate here and, in turn, the recipe won't turn out the same.
Hope this helps.
Manisha says
Many thanx Helen
I also use only callebaut dark for everything. It is a bittersweet variety with not very high coco content. Will stick with this chocolate to make these brownies :)