To Prep Cake Batter
- Line bottom of 18cm round cake pan with 1 layer of parchment paper. Do not grease the cake pan.
- Preheat oven to 175°C.
- Bring milk to a boil and remove from heat. Add tea bags and steep for 30 mins. Strain out tea. Squeeze out as much liquids from the tea as possible. Discard tea bags. Set aside until cool.
- Whisk caster sugar and egg yolks together until well combined. Mix in melted butter. Add chai latte, orange zest and vanilla extract. Whisk together thoroughly.
- Sift over ground spices, cake flour, baking powder and salt into the mixture. Whisk until all ingredients are combined with no lumps.
To Prep Meringue
- With an electric mixer, whisk egg whites until frothy. Add cream of tartar. Whisk until thick foam forms. Slowly add caster sugar. Continue to whisk until firm peak stage.
To Combine Cake Batter and Meringue
- Gently fold in meringue to the cake batter in 4 batches. Mix until well combined.
- Gently pour batter into cake pan.
- Shake cake pan side to side until batter is level, tapping pan against the bench top to remove air bubbles.
- Place on medium rack of oven, bake for 20 mins until golden brown on top or until tooth pick comes out clean.
- Remove cake from the oven, leave to cool. Using a butter knife, gently slice through the side of the cake pan to loosen it. Unmould cake to a cake board and remove parchment paper. Peel off the cake skin on top of the sponge cake. Use a cake leveler or serrated knife to slice the cake into 3 even layers.
To Prep Salted Palm Sugar Swiss Meringue Buttercream
- In a saucepan, mix palm sugar, pandan leaves and water. Bring to boil on medium.
- Stir continuously until the sugar is completely melted and slightly reduced. Turn off the heat, strain and discard the pandan leaves. Let sit to cool. The syrup will thicken as it cools.
- Cut the butter into cubes. Set aside to room temperature.
- Place a heat-proof bowl over a pot of simmering water, making sure that the bowl is not in contact with the water. Combine egg whites and sugar and use a hand whisk to whisk until the sugar is dissolved. Check if there is any unmelted sugar by rubbing the mixture between your fingers.
- Transfer the mixture to a mixer bowl and beat over high speed with whisk until stiff peaks. Let cool to room temperature, or place in the fridge to speed up the cooling process. Cooled meringue will prevent the butter from melting.
- Set the mixer to low speed, then gradually add in the butter cubes. Turn to high speed and beat until the mixture is well combined. Scrape the bowl if necessary. It might look curdled at one stage but keep beating until it turns into a smooth buttercream.
- Add the vanilla extract and salt until well combined.
- Lower the speed and add the palm sugar caramel one teaspoon at a time. Use a spatula to scrape the bowl, beat until well combined.
To Assemble the Cake
- Spread a layer of the buttercream on top of a slice of sponge cake. Then stack the second cake on top. Spread the buttercream on top again and repeat for the third layer.
- Coat the entire top of the cake with the buttercream. Coat lightly on the side of the cake in semi-naked style or fully coat the entire cake.
- Sprinkle crushed pistachio and orange zest on top of the cake. Serve.
- Optional: Pipe rose swirl with buttercream using 1M piping tip.