Chocolate Mirror Cake

One of the things I love about my family is how often we gather for celebrations.  For most folks, January is a welcome break from the jam-packed holiday season that is Thanksgiving through New Years.  In my family however, we hit the new year running.  Almost every month of the year provides us with a great excuse to get together and eat some cake. January is a birthday party, February brings Valentine’s Day and Hubby’s birthday.  Although throwing a party for Hubby is a bit of a tug of war.  He doesn’t like to have a party held for him…and my mother is adamant on throwing him a party every year.  Last year she said, “we are throwing you a party, you can show up if you want”.   You gotta love her for the fact that she will shower you with love and great food wether you want it or not.

I first made this cake for my step-father’s birthday party in January, and I’ve made it again for Valentine’s Day.  When I was thinking of what to make for the January birthday party, I had asked myself, what kind of cake do you make for a man who loves strong, dark and bitter chocolate?

That’s when I decided a dense, flourless chocolate cake, enriched with espresso and topped with a glossy, midnight-black glaze was going to be the perfect cake to top off our celebration.  Now I’m a milk chocolate fan myself, so I figured this cake would be a bit too dense and dark for me, but I loved the taste and it became a huge hit at the party.  So when I was thinking of what to make for a great Valentine’s day dinner, I turned right back to this cake.

This is the first time I have hosted a large party and not been an exhausted ball of stress by the end of the evening. The secret seemed to be delegating. The only thing I made was the cake and I made it two days before the party even started.   My family is huge on potlucks and I can’t help but wonder what took me so long to catch on.  Maybe my parents have had enough experience to realize that hosting a potluck is the way to go.  What’s not to love? It get’s everyone involved and leaves the host with enough energy to enjoy the evening as most as anyone else.  My family even goes the extra step of helping cleanup afterwards, so all I really had to worry about was the cake.

DARK CHOCOLATE MIRROR CAKE

This recipe is adapted from two great resources, The cake is inspired from America’s Test Kitchen.  I’ve adapted the size of the cake pan I use to be a smaller 8-inch springform pan instead of a 9-inch, so the cake comes out a bit thicker.  I also added some instant espresso powder to bump up the intensity and baked the cake at a slightly lower temperature for a longer period of time so the cake comes out softer.  I happened upon the glaze recipe by a renowned pastry chief, Michael Laiskonis. I found it on a blog of his, but unfortunately the link is no longer active, but he is an award-winning pastry chief so do a google search on him.  It’s the smoothest glaze I have ever come across, and he gets all the credit.


This cake is rich and dense.  I noticed at the birthday party that most people only finished half of their cake,and seeing ten half-eaten pieces of delicious chocolate cake was a sad sight.  So thin pieces are good to start with…you can always go back for more.

RECIPE

Adapted from: America’s Test Kitchen “Bittersweet Chocolate Mousse Cake” and from Michael Laiskonis “Chocolate Glaze”.

Serves 10-12

INGREDIENTS

     Cake

          13  ounces bittersweet chocolate chips

           12  tablespoons unsalted butter (1 1/2 sticks, 170 grams), cut into 12 pieces

       3/4  teaspoon instant espresso powder

            8  eggs, separate the yolks and egg whites

              1  tablespoon vanilla extract

        1/8  teaspoon table salt

        2/3  cup packed light brown sugar (4 1/2 ounces), crumbed to remove lumps

                  softened butter, for greasing the pan

                  all purpose flour, for greasing the pan

 

    Glaze

              packages of powdered gelatin  (about .50 ounces or 14 grams)          

          80  grams cold water  (2/3 cup + 2 tablespoons)

     280    grams heavy cream  (1 cup + 1 tablespoon)

         65   grams water (1/2 cup)

      420   grams sugar (2 cups)

       140   grams dutch cocoa powder  (1 cup + 2 tablespoons) 

 * you will end up with lots of leftover glaze, but you need a lot of extra glaze to pour it smoothly onto the cake.

 

INSTRUCTIONS

1. Preheat the oven to 300 degrees (149 degrees celcius) and adjust the rack to the lower-middle position.

2.  Fill a pot half way with water and bring to a low simmer.  In a large bowl, add 13 ounces bittersweet chocolate, 12 tablespoons of butter and espresso powder. Place the bowl over the pot of simmering water (water shouldn’t be touching the bowl).  Let the chocolate mixture melt, stirring occasionally until smooth.  Set the melted chocolate aside to cool while you separate the eggs.

3.  Separate 8 eggs. Stir the egg yolks into the melted chocolate mixture, along with 1  1/2 teaspoons vanilla extract.

4. Add the egg whites along with 1/8 teaspoon salt  (just add two pinches of salt) into the bowl of an electric mixture.  You can also use a hand-held electric whisk. Doing this all by hand is hard work…but great exercise.). Whisk the egg whites for a few seconds until you see bubbles form around the sides of the bowl.

5. Measure  3/4 cup of tightly packed light brown sugar (about 4 1/2 ounces if your are weighing your ingredients).  Add half the brown sugar to the egg whites and whisk on the highest setting for 30 seconds, just to incorporate the sugar.  Add the rest of the brown sugar and whisk on the highest setting until you get “soft peaks”, which takes about one and a half to two minutes.

6. Prepare the cake pan by buttering the sides and bottom of an 8-inch springform cake pan.  Flour the sides and tap out any excess flour. Line the bottom of the pan with parchment or wax paper (trace the bottom of the cake pan onto the paper and cut out the circle).  Do the same thing with some spare cardboard to create a homemade cake round. Wrap the bottom and sides of the pan in two large sheets of foil. This will keep out water during baking

7. Pour the cake mixture into the pan.  Place the cake pan in a large casserole dish or on a baking sheet which has tall sides.  Fill with water until the pan is covered about half way.   It’s easier to have the cake near the oven when filling with water so you don’t have to move the pan around once it is full of liquid.

8. Bake until the top of the cake no longer jiggles.  About 45 minutes to an hour.

9. Remove the pan from the oven (be careful of the hot water!)  and place the cake on a cooling rack for 10 minutes.

10. After 10 minutes, use a small knife to cut between the cake and the cake pan, so that when it cools it doesn’t stick to the pan and crack.  Let it cool to room temperature, about 3 hours.  After the cake has cooled, cover the top of the cake pan with plastic wrap and place it in the refrigerator for an hour, or overnight

11. Release the cake from the springform ring and flip onto your cardboard cake round.  Trim the round if its a little larger than the cake, otherwise the glaze with gather onto the excess cardboard.  Peel off the parchment paper.

 

You can store the cake for future use by covering the top with plastic wrap (make sure the plastic wrap is touching the cake, no air pockets.  Store the cake in the refrigerator for two days, or in the freezer for a month.

TO MAKE THE GLAZE

1. Cover the powdered gelatin with the cold water. 

2. Add the cream, water and sugar to a pot and bring to a low simmer. Remove from heat and add gelatin and cocoa powder.  Whisk it together and blend until smooth.

TO GLAZE THE CAKE

1.  While the glaze is still hot, pour it generously over the cake.  Do one continuous pour, otherwise the glaze looks a little bumpy.  Start in the center and pour around the sides of the cake

2. Let the glaze drip for a minute and then scrape of any dripping chocolate from below the cardboard.   Store in the refrigerator unless serving immediately.

 

I like to gather up all the left over glaze, refrigerate it and enjoy a spoonful from time to time.  You can also refrigerate the glaze and keep the extra for use in a future dessert. The glaze can be made ahead of time, just reheat the glaze until it can be easily poured.

EXTRA TIPS

To melt chocolate mixture using micowave:

melt the chocolate mixture in the microwave for about 2 minutes, taking it out every 15 seconds to stir.  Only microwave until the mixture is smooth and melted (1 or 2 minutes, depending on your microwave).

 

What Are Soft Peaks?

Short Answer: When you lift up your whisk, the egg whites will curve over the side of the whisk.  If the peak is standing standing straight up, you’ve over whipped it.

Long Answer: The longer you whip egg whites the more fluffy and firm they become. If you gather some egg whites on your whisk and lift it up, it should be firm enough to stay on the whisk and not fall off.  When you lift up the whisk a peak will form and depending on how much you have whipped your eggs, the peak will bend off to the side (a soft peak) or stand straight up (a firm peak).  A firm peak will be too structured for this cake and actually cause it to over rise when baking, so a soft peak is important.

 

Troubleshooting

My cake puffed up a lot when baking: you probably over whipped your egg whites

My glaze is not smooth: It really helps to have way too much glaze when you are pouring the cake.  It allows to you generously pour and cover the cake.  You will feel like you are left with a pan filled with delicious chocolate, but just pour it into a container to use another time…or to eat spoonfulls at a time…not that I ever do that…

Can I make the cake sweeter?  Yes, just use less espresso powder or swap the bittersweet chocolate for semisweet chocolate or even milk chocolate.

 

2 Comments

  1. 2-16-2013

    Watched this with my 3 year old who was quite impressed when you flipped the cake over onto the cardboard. I didn’t know she was paying attention, but she said, “Oooh, so that’s how she does it!” at that part. At the end she said, “Now I can make you a chocolate cake, mama.” I was impressed with your egg white/yolk separation…you make it look so easy! This cake looks delicious and I’m trying to think of the perfect occasion to make it.

    • 2-17-2013

      Thanks Christine! It’s so fun to discover the parts of the recipe which other people find fascinating. I hope she does make it for you. I thought attempting this cake would be a lot of work, but it wasn’t anything too complicated. Thanks for sharing :)

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