Chocolate Sheet Cake with Milk Chocolate Buttercream Icing

After an almost two month hiatus from running, one that felt like an eternity, I ran for the first time last weekend. As I was getting ready for this long awaited return to running, you would have thought I was about to run some high stakes or challenging course race. I felt queasy, nervous, and overly anxious about a two mile run. Yes, just two short freakin' miles. But in my post injury head, it wasn't only this distance I was worried about. No, what was taking up even more worry space in my mind was whether or not I would re-injure myself. As well as whether my body was truly healed or was it a case of wishful thinking. The bad news, relatively speaking, was my running pace was slower and much more labored than it had been before the injury. And the good news? After getting myself into a pre-run tither, it was a pain free run. I was simultaneously bummed about my pace and elated over the absence of wincing discomfort. Which I suppose you could say the glass was half-full, maybe a little more than half full. Having this 'first' post-injury run now behind me, I continue to be hopeful any lingering trepidation, including the queasiness, will continue to fade each time I go out for a run. I have only three months to rebuild up my endurance and speed (again relatively speaking). In early June, we have a destination run on the east coast. A ten miler. Piece of cake, right?

Speaking of cake, I have only recently become a big fan of the homemade sheet cake. This would be a significant shift from my love for and loyalty to layer cakes. Like a slab pie, there is something irresistible about a sheet pan cake. It's rustic and humble in its' presentation, yet so incredibly appealing. And so much easier to cut than a layered cake! Particularly when someone says they only want a very small sliver (really? chocolate cake with chocolate frosting and someone requests only a sliver? crazy!). This, however, may be one of those cakes where anyone with unswayable self-control will be requesting a second sliver. The taste of the icing alone will have them giving it up.

As much as I love this chocolate cake, it's the 'icing on this cake' that I am deeply, madly in love with. Paired together they are a match made in heaven.

After indulging myself with a small piece of this Chocolate Sheet Cake with Milk Chocolate Buttercream Icing I cut it up into pieces and gave it all away. I regretted this random act of kindness as soon as I got home with my empty baking sheet. Oh, how I wanted to have another piece of this insanely delicious cake!

The recipe for this one bowl chocolate cake has become one of recent favorites. Previously I had only made it as a two layer cake. However, there is enough batter in the recipe to make a 9"x12" or 9"x13" sheet pan cake.

This cake's deep, dark color comes from both the Dutch-processed cocoa and the coffee. These two ingredients create a cake with the most perfect color to contrast to the Milk Chocolate Buttercream Icing. As a side note, if you ever come across a recipe for a chocolate cake calling for warm water, replace with it a cup of coffee. Not only will the coffee intensify the flavor of the chocolate, it will deepen the color of the baked cake.

This Milk Chocolate Buttercream Icing is velvety smooth, glossy, and creamy delicious. The recipe makes enough to generously frost the sheet cake. You might even have a spoonful or two left to secretly enjoy.

Whip the icing using either a standing mixer with a whisk attachment or with a hand held mixer. The addition of heavy whipping cream adds suppleness, lusciousness, and richness to this Milk Chocolate icing.

The use of an offset spatula or large spoon to swirl the icing on top of the sheet cake makes the most beautiful swoopy looking cake. If you want a fancy, fussy finish, pipe on the icing using a pastry bag and your favorite pastry trip.

Top with sprinkles or not top with sprinkles? That was the question. After some deliberation, I decided the Chocolate Sheet Cake looked sexier without them and more whimsical with them. So depending on your mood or the one you are trying to create, either leave them off or sprinkle them on. Or if you can't really decide, serve the cake with a bowl of them on the side and let everyone choose for themselves. Several years ago, I came across the Callebaut's Chocolate Crisp Pearls for the first time in an incredible chocolate shop in Boulder, Colorado. Ever since then, they have been my favorites.

The next time you want to make a cake for your family and friends or to simply give it away, make this Chocolate Sheet Cake with Milk Chocolate Buttercream Icing. Or ice it with the Peanut Butter Frosting used in the making of the layered Chocolate Peanut Butter Cake. I promise, whether you frost this cake with a rich, creamy milk chocolate icing or a smooth, lush peanut butter icing, everyone will go wild for your sheet cake! 

If serving to a large crowd, consider serving it on a large wooden board rather than in the pan or on a platter. Note: Don't remove the parchment paper if serving it on a wooden board.

Recipe
Chocolate Sheet Cake with Milk Chocolate Buttercream Icing (minor changes to Julia Turshen's Happy Wife, Happy Life Chocolate Cake recipe as shared in her cookbook "Small Victories: Recipes, Advice, and Hundreds of Ideas for Home-Cooking Triumphs")

Serves 16-20  people, depending on how you slice it

Ingredients
Cake
1 1/4 cups (160 g) all-purpose flour 
1 cup (200 g) granulated sugar
3/4 cup (75 g) Dutch-processed cocoa powder, sifted if lumpy
1 teaspoon baking soda
1 teaspoon baking powder
1/2 teaspoon kosher salt
8 Tablespoons (113 g) unsalted butter, melted and cooled
2 large eggs, room temperature
1 cup strong black coffee cooled or 1 rounded teaspoon espresso powder mixed into 1 cup boiling water then cooled
1 cup buttermilk
1 teaspoon good quality vanilla

Icing
1 cup (8 ounces) unsalted butter, room temperature
1 1/2 cups (188 g) confectionary sugar, sifted
2 teaspoons vanilla
8 ounces good quality milk chocolate, chopped, melted. and slightly cooled
Pinch of sea salt or Kosher salt
2-3 Tablespoons heavy whipping cream
Optional: Chocolate Crisp Pearls (Recommend the ones made by Callebaut) or Chocolate Sprinkles

Directions
Cake
1. Preheat oven to 350 degrees (F). Line a  9"x13" or 9"x12" baking pan with parchment paper. Lightly butter and/or spray top of parchment paper and sides of pan if not covered with parchment paper.
2. In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.
3. Add melted butter, eggs, coffee, buttermilk, and vanilla. Whisk until batter is thick and smooth.
4. Pour batter into prepared baking pan. Lightly tap the cake pan to remove any air bubbles.
5. Bake until top of cake spring back when lightly pressed and edges begin to come away from the pan. Approximately 25-30 minutes of baking time.
6. Transfer cake pan to a wire rack and allow to cool completely before icing.

Icing and Assembly
1. In the bowl of a standing mixer fitted with a whisk attachment (or a hand held mixer), beat butter and confectionary sugar on medium-high speed until creamy (approximately 2 minutes).
2. Scrape down sides of the bowl, add vanilla and salt. Mix on low until incorporated. 
3. With the mixer on low speed, beat in melted, cooled milk chocolate until all is incorporated. Stop to scrape the bowl as needed. Increase speed to medium high and beat until light and fluffy (approximately 2-3).
4. Add heavy whipping cream and beat until light and fluffy. Approximately 3-4 minutes.
5. Spread icing evenly over the top of the cake. Swirl icing with a spoon or offset spatula. Alternately put icing in a pastry bag fitted with pastry tip of choice. Optional: Top with Chocolate Crisp Pearls or Sprinkles.
6. Serve immediately or store in the refrigerator until ready to serve. Allow the chilled cake to sit out at least 30 minutes before serving.

Notes: (1) For the flour weight calculation, I used the 128 g per cup equivalent. (2) I am partial to a chilled cake, so I like to eat it right out of the refrigerator. (3) Can melt chocolate over a double boiler or in the microwave. Make sure to chop the chocolate evenly before melting. I used the Trader Joe's Milk Chocolate for the icing.