Prepare The Cake Batter

1. Preheat the oven to 160°C fan. Prepare an unlined, ungreased 7-inch chiffon cake pan. Do not grease the pan, as the cake needs to cling to the sides while baking.
2. Separate the eggs, placing the egg whites in a large, clean, grease-free mixing bowl and the egg yolks in a separate medium-sized bowl.
3. Heat the milk in the microwave for 45–60 seconds, or until hot. Add 2 chai tea bags, cover, and leave to steep for about 5–10 minutes. Remove the tea bags and allow the infused milk to cool before using.
4. In a medium mixing bowl, beat the egg yolks and 20 g caster sugar until pale and almost doubled in volume.
5. Add the vegetable oil and cooled chai-infused milk. Continue beating at medium speed until the mixture is smooth and fully emulsified.
6. Sift in the cake flour, cinnamon, nutmeg and salt. Mix gently at low to medium speed until just combined. Avoid overmixing.
7. Cut open the remaining 2 chai tea bags and add the dried tea leaves to the batter. Use a silicone spatula to gently mix until evenly distributed.

Make The Meringue

1. Add a few drops of lemon juice to the egg whites. Using a clean, grease-free whisk attachment, whisk until foamy.
2. Gradually add the 50 g caster sugar in three additions, whisking for about 30 seconds to 1 minute between each addition to allow the sugar to dissolve.
3. Once all the sugar has been incorporated, increase the mixer to medium-high speed and continue whisking until stiff, glossy peaks form.

Combine The Batter

1. Add a small amount of the meringue to the egg yolk batter and gently fold it in to lighten the mixture.
2. Gradually add the remaining meringue in small batches, gently folding after each addition until no white streaks remain before adding the next batch. Take care not to deflate the meringue.
3. Pour the batter into the ungreased chiffon pan, preferably in one spot, allowing the batter to spread naturally.
4. Lift the pan a few centimetres above the counter and gently drop it once or twice to release any large air bubbles.
5. Run a skewer through the batter in a circular motion to release any smaller air pockets. Gently shake the pan from side to side to level the surface.

Bake And Cool The Cake

1. Bake in the preheated oven at 160°C fan for 35–38 minutes, or until a skewer inserted into the centre comes out clean.
2. Immediately remove the cake from the oven and invert the pan. Allow the cake to cool completely upside down. This prevents the delicate chiffon cake from collapsing as it cools.
3. Once completely cooled, gently run a thin spatula around the outer edge of the cake and around the centre tube to release it from the pan.
4. Run the spatula around the base of the pan to release the cake completely.
5. Place a serving plate or cake stand over the pan, then carefully turn the pan upside down. The cake should release cleanly.

Make The Vanilla Mascarpone Frosting

1. Combine the icing sugar and salt in a small bowl and mix well.
2. Add the clear vanilla extract to the double cream and mix briefly to combine.
3. Place the mascarpone and icing sugar mixture in a large mixing bowl. Use a silicone spatula to roughly combine.
4. Using a handheld mixer fitted with a whisk attachment, whisk the mascarpone mixture for about 10–15 seconds to loosen it.
5. With the mixer running, gradually pour in the vanilla-infused double cream. Continue whisking until the frosting reaches medium peaks. Be careful not to overwhip.
6. Cover and refrigerate until ready to use.

Decorate The Cake

1. Once the cake has completely cooled, cover the entire cake with a layer of vanilla mascarpone frosting, including the centre funnel. Smooth the frosting as evenly as possible.
2. Chill the cake for about 10 minutes to allow the frosting to firm up slightly.
3. Transfer the remaining mascarpone frosting to a piping bag fitted with a French piping tip. Pipe seven decorative dollops evenly around the top of the cake.
4. Lightly dust the frosting and cake with ground cinnamon.
5. Cut Biscoff biscuits in half and gently insert one half into each piped frosting dollop.
6. Slice and serve your beautifully decorated Chai Tea Chiffon Cake.