Light Ginger Chiffon Cake with Rich Vanilla Custard

Preheat the oven to 160°C (320°F) with an oven rack positioned in the center.

Cut a round of parchment paper using a chef knife and line the base of a 20 cm round loose-bottom cake tin, leaving the tin sides completely ungreased.

Sift cake flour, ground ginger, ground cinnamon, ground cloves, baking powder, and 2 g fine sea salt through a fine-mesh sieve into a medium mixing bowl.

Finely grate the fresh ginger root using a microplane grater, squeeze firmly to extract 15 ml of clear ginger juice, and whisk the juice with 4 egg yolks, 50 g caster sugar, vegetable oil, whole milk, and vanilla extract in a large mixing bowl until smooth.

Add the sifted flour and spice mixture into the yolk base and fold with a silicone spatula until incorporated into a lump-free, thick batter.

Whip 4 egg whites and cream of tartar in a stand mixer with whisk attachment on medium-high speed until soft peaks form, then slowly rain in 100 g caster sugar over 1 minute and whip until glossy, firm peaks hold.

Scoop one-third of the whipped meringue into the spiced yolk batter and fold thoroughly with a silicone spatula to loosen the batter density.

Add the remaining meringue in two additions and fold gently with the silicone spatula using sweeping bottom-to-top strokes until the batter is homogeneous and light.

Pour the batter into the prepared cake tin, gently drop the tin onto the counter once from a height of 5 cm to dislodge large air pockets, and bake in the oven at 160°C (320°F) for 35 minutes.

Remove the cake from the oven, place the tin onto a wire cooling rack, cool for 25 minutes, then run a thin chef knife along the inside edge and unmold the sponge.

Split the vanilla bean lengthwise using a chef knife, scrape the seeds, and heat heavy cream, whole milk, vanilla pod, vanilla seeds, and 1 g fine sea salt in a medium saucepan over medium heat until tiny bubbles appear around the rim at 75°C (167°F).

Whisk 4 custard egg yolks and 60 g caster sugar together in a medium mixing bowl using a whisk until pale, thickened, and slightly ribboned.

Pour approximately half of the hot milk-cream mixture into the egg yolk mixture in a slow, steady stream while whisking continuously with the whisk to temper the eggs.

Pour the tempered egg mixture back into the medium saucepan and cook over low heat while stirring continuously with a silicone spatula across the bottom and edges until the custard thickens and reaches 82°C to 84°C (180°F to 183°F).

Remove the saucepan immediately from heat and strain the warm custard through a fine-mesh sieve into a clean medium mixing bowl to capture the spent vanilla pod and any coagulated chalazae.

Portion the ginger cake into 8 wedges using a chef knife, place onto serving plates, and use a ladle to spoon warm vanilla custard sauce generously around each warm slice.