Marble Bundt Cake (White Chocolate and Cocoa)

The original recipe called for baking it in a 15-cup Bundt pan. I only had a 12-cup Bundt pan and it baked up perfectly in that size as well. Either size will work. The cake will be a bit taller in a 12-cup pan. Note that the oven is NOT preheated for this cake. It goes into a cold oven, which gives the batter extra time to rise, producing an extra-smooth, tender crumb. This cold oven method is great for cakes that do not contain any baking soda or baking powder.

White Chocolate Batter:
8 oz (2 sticks) butter, removed from fridge 30 minutes before baking (227 g)
1⅓ cups (10.5 oz) Monk Fruit Sweetener with Erythritol (Granular) (300 g)
4 large eggs whites, at room temperature (120 g)
1½ tsp. vanilla bean paste or pure vanilla extract
white chocolate, melted and slightly cooled (113 g)
cake and pastry flour, such as Anita's (187 g)
1 tsp. sea salt

Chocolate Batter:
8 oz (2 sticks) butter, removed from fridge 30 minutes before baking (227 g)
1⅓ cups (10.5 oz) Monk Fruit Sweetener with Erythritol (Granular) (300 g)
4 large egg yolks, room temperature (74 g)
2 large whole eggs, room temperature (100 g)
1½ tsp. vanilla bean paste or pure vanilla extract
½ cup (2.25 oz ) black cocoa powder, sifted (64 g)
¾ cup (3.3 oz) cake and pastry flour, such as Anita's (94 g)
1 tsp. sea salt
⅓ cup (4.25 oz) buttermilk, room temperature (120 g)

White Chocolate Glaze:
¾ cup (5 oz) white chocolate, chopped (150 g)
2 Tbsp. milk
1 Tbsp. butter
¼ tsp. sea salt, optional

Chocolate Glaze:
½ cup (4 oz) chocolate or chocolate chips (milk, semi-sweet, or bittersweet), chopped (120 g)
2-3 Tbsp. milk, such as almond milk, canned coconut milk or heavy cream
½ Tbsp. butter or coconut oil
1-2 tsp. pure maple syrup, pure honey or confectioners' sugar

Make the White Chocolate Batter:
In the bowl of a stand mixer fitted with the paddle attachment, cream butter and sugar at medium speed until fluffy and pale, 6-8 minutes, stopping to scrape sides of bowl. Add egg whites, one at a time, beating well after each addition, about 15 seconds. Beat in vanilla. Scrape the bottom and sides of the bowl with a rubber spatula. With the machine on medium-high speed, add the melted white chocolate, beating until smooth, about 1 minute. Add the flour and salt and stir by hand with a rubber spatula until just combined. Transfer the white batter to a large bowl and set aside. Wash the mixer bowl and paddle attachment. Return the bowl to the stand mixer.

Make the Chocolate Batter:
Using the paddle attachment, beat the butter and sugar at medium speed until fluffy and pale, about 6-8 minutes, stopping to scrape sides of bowl. Add whole eggs, one at a time, beating well after each addition, about 15 seconds. Add egg yolks, two at a time, beating well after each addition, about 15 seconds. Beat in the vanilla. Scrape the bottom and sides of the bowl with a rubber spatula. Increase the mixer to medium-high and beat until smooth, about 1 minute. Turn the mixer to low speed and the black cocoa, flour and salt; beat until smooth. Add buttermilk, beating just until batter comes together. Scrape the bottom and sides of the bowl with a rubber spatula and stir just until combined.

Spray a 12-cup or 15-cup Bundt pan with baking spray with flour.

Using a two or three ounce spring-loaded ice cream scoop, dollop the vanilla and chocolate mixtures alternately into the pan like a chess board - first next to each other, then in layers on top of each other. When done, insert a knife all the way down and swirl the batter gently. Avoid mixing to the point where all the batter turns all chocolaty defeating the marble design and distinct flavours of each.

Tap pan on kitchen towel-lined counter a few times to settle batter and release any air bubbles.

Place the pan in a cold oven and bake at 300°F (150°C/130°C fan, Gas Mark 2) until lightly browned on top and a wooden skewer inserted near the center comes out clean, about 1 hour and 20 minutes. If the skewer comes out wet, continue baking and checking at 5-minute intervals.

Let cool in the pan for 10 minutes. Invert cake onto a wire rack and let cool completely before slicing and serving.

Make the Chocolate Glaze:
Combine the chocolate, 2 Tbsp. milk and butter in a double-boiler, stirring until the chocolate is fully melted. Add additional warm milk if needed to thin. Remove from the heat. Taste, then stir in your sweetener of choice, if desired.

Make the White Chocolate Glaze:
Combine the white chocolate, milk and butter in a double-boiler, stirring until the chocolate is fully melted. Remove from the heat. Let the glaze come to room temperature to thicken. Whisk and taste for sweetness, add a pinch of sea salt, if necessary.

Assembly:
Pour the chocolate glaze over the cake and let it stand until hardened, about 15 minutes. Pour the white chocolate glaze over the top and let it stand until hardened, a further 10-15 minutes.

Makes 12 servings.

Cook's Notes:

For the marble effect, alternatively spoon chocolate and vanilla batter into the pan using a measuring scoop or an ice cream scoop (imagine a chess board). Then, swirl the batter by running a knife or skewer through it - either in circles or just back and forth. Don’t worry if it looks like a mess, because I can guarantee you it will. Also, don’t overdo it or the batter will turn all chocolaty (which sounds delicious, but defeats the purpose).