Marble Cake

Before you start

Marble cake is one butter cake batter split in two, with cocoa stirred into one portion. Layering the two batters and swirling them briefly gives each slice a pattern of vanilla and chocolate. A good marble cake tastes like both, not like a muddy compromise, and the swirl stays sharp because the two batters have the same thickness.

Matching the batters is the trick. Cocoa powder absorbs liquid and makes the chocolate portion stiffer, so mix it into a paste with a little hot milk before adding it. That keeps the chocolate batter as loose as the vanilla, so they flow around each other instead of sitting in separate lumps. Then swirl with restraint: a few passes with a knife, not a stir.

Ingredients

• Batter225 g (1¾ cups + 1 tbsp) all-purpose flour
• 1½ tsp baking powder
• ½ tsp fine salt
• 170 g (¾ cup) unsalted butter — softened
• 200 g (1 cup) granulated sugar
• 3 large eggs — room temperature
• 2 tsp vanilla extract
• 120 ml (½ cup) whole milk — room temperature
• Chocolate paste20 g (¼ cup) Dutch-process cocoa powder
• 1 tbsp granulated sugar
• 3 tbsp hot milk or hot coffee

Method

1. Heat the oven to 175°C (350°F). Grease the loaf pan and line it with a parchment sling that overhangs the long sides.
2. Stir the cocoa, 1 tbsp sugar and hot milk into a smooth paste. Set aside to cool. Whisk the flour, baking powder and salt together.
3. Beat the butter and 200 g sugar on medium-high speed for 3 to 4 minutes, until pale and fluffy. Beat in the eggs one at a time, scraping the bowl after each, then the vanilla.
4. On low speed, add the flour mixture in three additions, alternating with the milk in two, and mix just until smooth.
5. Move about 40 percent of the batter (roughly 350 g) to a second bowl and stir in the cocoa paste until even. Both batters should have a similar soft, spoonable texture.
6. Drop large spoonfuls of the two batters into the pan, alternating them like a checkerboard, in two layers. Run a knife through the batter in 4 or 5 loose figure-eights, reaching to the bottom of the pan. Stop there.
7. Bake for 55 to 65 minutes, until the top is domed and cracked and a toothpick in the center comes out with a few moist crumbs but no wet batter.
8. Cool in the pan for 15 minutes, lift it out using the parchment, and cool completely on a rack before slicing.

Tips for success

• Weigh the batter and the bowls if you want consistent results; the 60/40 split gives a cake that reads as vanilla with bold chocolate ribbons.
• If the top browns too fast, lay a sheet of foil loosely over the pan for the last 15 minutes.
• More swirling is not better. After about six passes, the batters blur and the cake turns light brown all over.

Substitutions

Dutch-process cocoa

Natural cocoa works because baking powder leavens this batter. The chocolate swirl will be lighter and slightly more reddish.

Whole milk

Buttermilk gives a softer crumb and mild tang. Add ¼ tsp baking soda to the dry ingredients to balance its acidity.

Cocoa paste

Melt 55 g dark chocolate with 2 tbsp milk and stir it into the chocolate portion for a richer, fudgier swirl.

Variations

Marble Bundt cake

Double the recipe and bake it in a greased and floured 10- to 12-cup Bundt pan for 55 to 65 minutes.

Orange chocolate marble

Add the zest of 1 orange to the butter and sugar, and use hot coffee in the cocoa paste.

Troubleshooting

Chocolate sank into a separate layer

The chocolate batter was looser or heavier than the vanilla. Make the paste thick but pourable, and dollop the batters side by side instead of pouring one over the other.

No visible marbling

The batters were over-swirled. Limit yourself to a few figure-eights and do not stir.

Crumb is dry and crumbly

Too much flour or overbaking. Weigh the flour and start checking at 55 minutes.

Storage

Wrap the cooled cake well and keep it at room temperature for up to 4 days. Slices freeze well for up to 2 months; wrap individually and thaw at room temperature.

Safety notes

Raw batter contains raw egg and flour and should not be tasted. Contains wheat, egg and milk.