Vanilla Chocolate Marble Loaf Cake

This vanilla chocolate marble loaf cake is soft, moist, and beautifully swirled in every slice. After baking, it is soaked with a light vanilla syrup, then finished with a dark chocolate glaze and a milk chocolate marble effect for an elegant pastry-style finish.

Yield: about 8 slices
Prep time: 30 minutes
Bake time: about 55 minutes

Equipment

• Kitchen scale

• One loaf pan, about 8 inches / 20 cm

• Mixing bowls

• Whisk

• Rubber spatula

• Small saucepan

• Pastry brush

• 2 piping bags (optional)

• Wire rack

Ingredients

Marble loaf cake

• 154 g unsalted butter, room temperature (about 11 tbsp)

• 300 g granulated sugar (1 ½ cups)

• 4 g salt (about ¾ tsp)

• 2 large eggs

• 220 g heavy cream (about ¾ cup + 2 tbsp)

• 254 g all-purpose flour (about 2 cups + 2 tbsp)

• 6 g baking powder (1 ½ tsp)

• 1 tsp vanilla extract

• 20 g unsweetened cocoa powder (about 3 tbsp)

Vanilla syrup

• 120 g water (1/2 cup)

• 50 g granulated sugar (1/4 cup)

• ½ vanilla bean, optional

Dark chocolate glaze

• 180 g dark chocolate, finely chopped (about 6.3 oz)

• 30 g neutral oil, such as grapeseed, canola, or sunflower oil (2 tbsp)

Milk chocolate marble

• 50 g milk chocolate, finely chopped (about 1.8 oz)

• 7 g neutral oil (about 1 1/2 tsp)

Instructions

1. Make the batter

Preheat the oven to 330°F / 165°C, conventional Bake setting.

Butter and flour the loaf pan well.

Place the room temperature butter and sugar in a mixing bowl or the bowl. Beat until the mixture looks lighter.

Add the eggs one at a time, mixing well after each addition.

Set aside 20 g (about 1 tbsp + 1 tsp) heavy cream for the chocolate batter. Add the remaining 200 g (about 3/4 cup + 1 tbsp) heavy cream to the butter mixture and mix until incorporated.

Add the flour, baking powder and salt to the batter. Mix just until no visible streaks of flour remain.

Divide the batter as evenly as possible between two bowls.

Add the vanilla extract to the first bowl.

Add the cocoa powder and the 20 g reserved heavy cream to the second bowl. Fold each batter gently with a spatula.

For a more defined and even marble effect, transfer the vanilla and chocolate batters into two piping bags. If you don’t have piping bags, simply alternate layers of vanilla and chocolate batter with a spoon in the pan .

Pipe three lengthwise strips into the bottom of the pan:

• one strip of vanilla batter;

• one strip of chocolate batter;

• one strip of vanilla batter.

For the second layer, reverse the pattern:

• pipe chocolate batter over the first vanilla strip;

• vanilla batter over the chocolate strip;

• chocolate batter over the second vanilla strip.

Continue alternating the pattern in the same way until all the batter has been used. Run a skewer, chopstick, or the tip of a knife through the batter using gentle S-shaped motions.

Bake for approximately 50 to 55 minutes at 330°F / 165°C. A skewer or thin knife inserted into the center should come out without raw batter, although a few moist crumbs are perfectly fine.

2. Make the vanilla syrup

While the cake is baking, combine the water, sugar and vanilla bean in a small saucepan. Bring to a gentle boil and stir until the sugar has fully dissolved. Let the syrup cool slightly.

Once the cake comes out of the oven, let it rest in the pan for about 5 minutes.

Using a pastry brush or spoon, gradually brush or spoon all of the syrup over the warm loaf.

Let the cake cool slightly, then carefully remove it from the pan and allow it to cool completely. For easier glazing, refrigerate the loaf for 30 to 60 minutes. The cake should be completely cold before glazing.

3. Prepare the two glazes

Melt the dark chocolate and milk chocolate separately, either over a double boiler or in the microwave in short 15 to 20-second intervals.

Add:

• 30 g (2 tbsp) oil to the dark chocolate;

• 7 g (about 1 1/2 tsp) oil to the milk chocolate.

Stir each mixture until completely smooth and glossy.

Place the cold loaf cake on a wire rack set over a sheet pan or tray to catch the excess glaze.

Pour the dark chocolate glaze generously over the top, allowing it to flow naturally down the sides.

Before the dark chocolate begins to set, drizzle the milk chocolate glaze using a spoon, in several thin, irregular lines over the length of the loaf.

For the best texture, let the cake come back slightly toward room temperature before serving.

Mathilde's Tips

Keep both batters similar in consistency. Cocoa powder absorbs moisture, which is why a small amount of extra heavy cream is added to the chocolate portion.

Glaze the cake only when it is completely cold. If the cake is still warm, the chocolate glaze will become too thin and run off too quickly.

Use visual cues to check doneness. Ovens vary, so use the baking time as a guide. The center should be fully baked but still moist.

Storage

Keep the cake stored in an airtight container. At room temperature, it is best enjoyed within 3 to 5 days.

If your kitchen is particularly warm, you may refrigerate it. Let it sit at room temperature for about 30 minutes before serving.

You can freeze the whole loaf or individual slices for up to 3 months. For best results, freeze the cake before glazing. Keep the cake tightly wrapped in plastic wrap. To thaw, leave the wrapped cake at room temperature for a few hours.