Ingredients
Equipment
Method
- Bring the cold ingredients toward room temperature. Set out the eggs, soy milk, and baking margarine for about 30 minutes. The margarine should be soft enough to press with a finger but not melted.
- Preheat the oven. Preheat to 350°F / 175°C. Position a rack in the center.
- Prepare the pans. Lightly grease three 8 1/2 x 4 1/2-inch loaf pans. Line the bottoms and long sides with parchment.
- Combine the flour and sugar. In a very large bowl, mix the flour and granulated sugar briefly.
- Add the fats and vanilla. Add the softened baking margarine, 1/2 cup / 120 mL oil, and vanilla. Mix on low speed.
- Stop when coarse crumbs form. The mixture should look like coarse sand with small crumbs and some pea-sized clumps. Do not keep mixing until it becomes smooth batter.
- Reserve the crumb topping. Measure out exactly 1 1/2 cups of the crumb mixture and set it aside before adding any eggs or liquid.
- Add the baking powder, cinnamon, and salt. Mix these into the crumbs remaining in the large bowl.
- Add the eggs. Add all 4 eggs and mix on low until mostly incorporated.
- Add the soy milk. Slowly pour in the 1 cup / 240 mL soy milk and mix until a thick cake batter forms.
- Stop once smooth. The batter should be thick, creamy, pale, and spreadable. Do not beat for several extra minutes.
- Start the chocolate marble. In a medium bowl, whisk together the cocoa powder and confectioners' sugar so there are no large cocoa lumps.
- Add the chocolate oil. Whisk in the 1/3 cup / 80 mL oil. The mixture will still be extremely thick.
- Add boiling water gradually. Whisk in the 1/2 cup / 120 mL boiling water in several additions until the chocolate mixture is dark, glossy, thick, and pourable in a heavy ribbon.
- Divide the cake batter. Divide the vanilla batter evenly among the three prepared loaf pans. Use a scale if possible.
- Check the pan level. Before adding chocolate and crumbs, the pans should be no more than about two-thirds full. Hold back extra batter if your pans are smaller.
- Add the chocolate marble. Drizzle about one-third of the chocolate mixture over each loaf, spreading it across most of the surface rather than pouring it into one spot.
- Swirl gently. Use a knife or skewer to make about 5-6 loose passes through each loaf. Reach into the batter but do not vigorously stir.
- Finish with any remaining chocolate. If a little chocolate remains, drizzle it over the upper surface.
- Prepare the reserved crumbs. Use your fingertips to break the reserved crumbs into a mix of fine crumbs, small clumps, and a few larger pieces.
- Top the loaves. Divide the full 1 1/2 cups reserved crumbs evenly over the three loaves. Leave them loose; do not press them down.
- Bake. Bake at 350°F / 175°C for 50-55 minutes. Begin checking around 48 minutes.
- Check for doneness. Insert a long tester into a pale cake area rather than directly through a chocolate ribbon. It should come out clean or with a few moist cake crumbs, but no liquid vanilla batter.
- Check the surface. The center should spring back lightly, the crumb topping should look dry and lightly golden, and the edges may pull slightly from the pans.
- Cool in the pans. Let the loaves cool for about 20 minutes.
- Remove. Lift the loaves out using the parchment and place them on wire racks.
- Cool completely. Wait about 45-60 minutes before slicing so the chocolate marble can firm.
Notes
Make Ahead, Storage & Freezing
- Make ahead: Excellent made 1 day ahead; the chocolate and crumb texture improve after the loaves rest.
- Room temperature: Store airtight for up to 3 days.
- Refrigerator: Up to 5 days, though the crumb will become firmer.
- Freezer: Wrap completely cooled loaves or individual slices tightly and freeze for up to 3 months. Thaw while wrapped at room temperature.
