Checkerboard Cake

Method

1. Prepare the orange cream: in a saucepan, combine orange juice, water, and cornstarch. Whisk until smooth. Add sugar and grated orange zest. Place over heat, stirring until sugar dissolves. In a bowl, beat whole eggs and yolks. Once the mixture is hot but not boiling, add the eggs, stir, and bring to a boil for 1–2 minutes. Remove from heat, add butter, and stir until melted. Pour into a dish, cover with cling film, and refrigerate for at least 3–4 hours.
2. Prepare the soaking syrup: in a saucepan, combine sugar, water, and grated orange zest. Bring to a boil, stirring. Remove from heat, let cool slightly, then add orange juice and mix. Set aside.
3. Prepare the light cake layers: sift flour, potato starch, and baking soda into a bowl. Add sugar and a pinch of salt. In another bowl, mix oil, milk, yogurt, egg whites, lemon juice, vinegar, and grated orange zest. Pour the wet ingredients into the dry and mix until just combined. Divide the batter evenly between two greased cake pans of the same size. Bake in a static oven at 180°C for about 35 minutes.
4. Prepare the cocoa cake layers: sift flour, cocoa powder (replacing potato starch), and baking soda into a bowl. Add sugar and a pinch of salt. In another bowl, mix oil, milk, yogurt, egg whites, lemon juice, and vinegar (no orange zest). Combine wet and dry ingredients, divide between two greased pans of the same size. Bake at 180°C for about 35 minutes.
5. Let the cakes cool completely. Use a serrated knife to level the tops and remove the crusts, especially from the light layers, to achieve the proper colour effect.
6. Create the checkerboard pattern: using two round cookie cutters of different sizes, cut three concentric rings from each cake layer. Swap the centre rings between the light and cocoa layers to form alternating colours.
7. Assemble the cake: place the first checkerboard disk on a rack. Brush with the soaking syrup. Pipe or spread a layer of orange cream over it. Place the next disk (alternating colours) on top, brush with syrup, and spread cream. Repeat for all layers, finishing with the top layer. Brush the top with syrup. Refrigerate briefly.
8. Prepare the chocolate ganache: bring the cream to a boil in a saucepan. Remove from heat, add chopped chocolate, and stir until smooth. Pour about three-quarters of the ganache into a bowl and let it cool to about 50°C. Place the remaining ganache in the refrigerator to thicken for piping.
9. Apply the thick chilled ganache as a crumb coat: spread a thin layer over the top and sides of the cake, smoothing it evenly.
10. Pour the thinner ganache (at about 50°C) over the cake, allowing it to flow over the top and down the sides for a glossy finish.
11. Transfer the cake to a clean tray. Reserve the excess ganache and refrigerate it to thicken. Decorate the bottom edge of the cake with chocolate sprinkles.
12. Refrigerate the cake on a rack for at least one hour, then transfer to a serving plate.
13. Place the thickened reserved ganache in a piping bag fitted with a star nozzle and pipe a decorative border around the base of the cake.
14. Let the cake rest in the refrigerator for a little longer before serving.