Baking Martha's Marble Cake with White Chocolate Glaze

Another baked good off the list from efforts to bake every recipe in Martha Stewart's Baking Handbook. Number 6 out of 173 was not a random pick from a friend but a custom order. My dad had me bring the book over so he could choose his recipe; he picked two. He wanted Marble Cake with White Chocolate Glaze for his birthday cake and come Christmas I'll be making him Baking Soda Biscuits.

But first came the marble cake and my previously mentioned frustration with the Baking Handbook. A hard to find ingredient not being called out as such. The culprit? Dutch-processed cocoa. This is my third recipe from Martha's book involving cocoa powder. All three specified Dutch-processed cocoa. I used natural unsweetened cocoa in both the One Bowl Chocolate Cupcakes and the icing on the Black and White Cookies. For my dad, I decided to see if I could track down the correct cocoa. I could not find it at Kroger, Publix or Ingles. I did track down a box at Whole Foods...for TEN DOLLARS. Yep, this cocoa costs twice as much as natural baking cocoa. 

Not all Dutch-processed cocoas will say such on their label. The ingredients always tell the tale. Natural will only list cocoa. Dutch-process will list cocoa and either say Dutch processed, like above, or simply alkali. That's what your looking for: alkali.

What's the difference between the two baking cocoas? It gets a little scientific. Cocoa is an acid. Dutch-processed cocoa is treated with an alkali (a base) to raise its ph and make it neutral. It affects the flavor and color. Dutch-processed is more mellow and the color is darker. The most important thing it affects is the power to rise. Dutch-processed must be used in recipes containing baking powder to trigger a leavening action. All the references I found online say while there is a substitution formula from one to the other it is advisable to not pull the switcheroo and to stick with the type of cocoa called for. 

Natural cocoa (left) is lighter and bitter tasting; Dutch-processed cocoa (right) is darker and milder in flavor.

I did not employ any special substitutions with my cupcakes. And they were gobbled up without notice about the chocolate flavor. I do wonder if using the right cocoa would've helped out with my chocolate icing issue on the black and white cookies. My chemistry is too rusty to determine the ph of the cream and whether the acid of the natural cocoa caused a runny instead of thick result. Only way to solve this query? Bake them again! Oh yes!

Marble Cake with White Chocolate Glaze
page 65 from the Martha Stewart Baking Handbook
Ingredients:

• 1/2 C unsalted butter, room temp, plus more for pan
• 1-3/4 C cake flour
• 2 t baking powder
• 1/2 t salt
• 1 C sugar
• 3 large eggs, room temp
• 1 t pure vanilla extract
• 2/3 C buttermilk, room temp
• 1/4 C plus 1 T Dutch-processed cocoa powder
• 1/4 C plus 2 T boiling water
• White Chocolate Glaze (recipe follows)

Directions:

1. Preheat oven to 350°F. Generously butter a 9-by-5-inch loaf pan; set aside. Whisk together the cake flour, baking powder and salt; set aside.
2. In the bowl of an electric mixer fitted with paddle attachment, beat the butter and sugar until light and fluffy, about 5 minutes. Add the eggs one at a time, beating until combined after each addition and scraping down the sides of the bowl as needed. Mix in the vanilla. Add the flour mixture in two batches, alternating with the buttermilk and beginning and ending with the flour. Set aside one-third of the batter.
3. In a bowl, mix the cocoa and the boiling water with a rubber spatula until smooth. Add the cocoa mixture to the reserved cake batter; stir until well combined.
4. Spoon the batters into the prepared pan in two layers, alternating spoonfuls of vanilla and chocolate to simulate a checkerboard. To create marbling, run a knife or skewer through the batters in a swirling motion. 
5. Bake, rotating the pan halfway through, until cake tester comes out clean, 40 to 50 minutes. Transfer pan to a rack to cool 10 minutes. Turn out cake from the pan and cool completely on the rack. Pour glaze over cake, letting it drip down sides. Cake can be kept in an airtight container at room temperature for up to 3 days.

Whisk together the flour, baking powder and salt.

Beat together the butter and sugar until...

...light and fluffy. Be patient. Takes about five minutes.

Add eggs, one at a time. Beat until combined after each one.

Add the flour mixture and buttermilk in alternating batches.

Set aside one third of the batter to be added to the chocolate.

The very expensive Dutch-processed cocoa.

So incredibly smooth. It indeed does dissolve better than natural cocoa.

Added to reserved batter and we have the makings of a chocolate cake.

Add batter in alternating spoonfuls...

...to make a checkerboard pattern.

Reverse flavors for second layer.

Twirl batter with a knife to create marbling. Do not overmix.

Cooling.

White Chocolate Glaze
Ingredients

• 3/4 C confectioners' sugar, sifted, plus more if needed
• 2 T milk, plus more if needed
• 2-1/4 ounces best-quality white chocolate, melted and cooled

Directions

1. In a small bowl, whisk together the confectioners' sugar and milk. The mixture should have the consistency of thin sour cream. Add the melted chocolate and whisk until glaze is smooth. If it is too thin, add more sugar, 1 tablespoon at a time; if too thick, add more milk, 1 teaspoon at a time. Use immediately.

Melted white chocolate.

Whisk together milk and sugar before adding cool, melted chocolate.

Pour on the glaze.

Cut, serve...

...enjoy.