Ingredients

For the Taro Sponge Cake:

  • 1 cup (120g) cake flour, sifted
  • 1 tsp baking powder
  • 1/4 tsp salt
  • 1/2 cup (120g) taro puree (from steamed taro root)
  • 1/4 cup (60ml) whole milk
  • 4 large eggs, separated
  • 3/4 cup (150g) granulated sugar, divided
  • 1/4 cup (60ml) vegetable oil
  • 1 tsp vanilla extract
  • 1/2 tsp purple food coloring (optional, for vibrant color)

For the Taro Custard Filling:

  • 1 cup (240ml) whole milk
  • 1/2 cup (120g) taro puree
  • 1/3 cup (65g) granulated sugar
  • 3 large egg yolks
  • 2 tbsp (15g) cornstarch
  • 1 tbsp (14g) unsalted butter
  • 1 tsp vanilla extract
  • Pinch of salt

For the Whipped Cream Topping:

  • 1 1/2 cups (360ml) heavy whipping cream, chilled
  • 1/4 cup (30g) powdered sugar
  • 1 tsp vanilla extract
  • Optional: Purple food coloring for aesthetic

For Garnish (Optional):

  • Crumbled taro sponge cake pieces
  • Edible flowers or fresh fruit (e.g., berries)
  • Toasted coconut flakes

Equipment Needed

  • 9-inch round cake pan
  • Mixing bowls
  • Whisk and spatula
  • Electric mixer or stand mixer
  • Medium saucepan
  • Cooling rack
  • Piping bag (optional, for decorating)

Instructions

Prepare the Taro Puree:

  1. Peel and cube 1 medium taro root (about 300g). Steam for 15-20 minutes until fork-tender.
  2. Mash or blend the steamed taro with a splash of milk (from the sponge cake ingredients) until smooth to make approximately 3/4 cup (180g) of taro puree. Set aside to cool.

Make the Taro Sponge Cake:

  1. Preheat the oven to 350°F (175°C). Grease and line a 9-inch round cake pan with parchment paper.
  2. In a medium bowl, whisk together cake flour, baking powder, and salt. Set aside.
  3. In a large bowl, beat egg yolks with 1/2 cup (100g) sugar until pale and thick (about 3 minutes). Add taro puree, vegetable oil, milk, vanilla extract, and purple food coloring (if using). Mix until smooth.
  4. Gradually fold the dry ingredients into the wet ingredients until just combined.
  5. In a clean bowl, beat egg whites with the remaining 1/4 cup (50g) sugar until stiff peaks form (about 4-5 minutes).
  6. Gently fold the egg whites into the batter in three additions, ensuring no streaks remain.
  7. Pour the batter into the prepared pan and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
  8. Let the cake cool in the pan for 10 minutes, then transfer to a cooling rack to cool completely.

Make the Taro Custard Filling:

  1. In a medium saucepan, heat the milk and taro puree over medium heat until steaming (do not boil).
  2. In a bowl, whisk egg yolks, sugar, cornstarch, and salt until smooth.
  3. Slowly pour the hot milk mixture into the egg mixture, whisking constantly to temper the eggs.
  4. Return the mixture to the saucepan and cook over medium heat, stirring constantly, until thickened (about 3-5 minutes). Remove from heat.
  5. Stir in butter and vanilla extract. Transfer to a bowl, cover with plastic wrap (touching the surface to prevent a skin), and chill for at least 2 hours.

Prepare the Whipped Cream Topping:

  1. In a chilled bowl, beat heavy cream, powdered sugar, and vanilla extract with an electric mixer until soft peaks form (about 3-4 minutes).
  2. If desired, add a drop of purple food coloring for a pastel purple hue. Continue beating until stiff peaks form.
  3. Transfer to a piping bag for decorating or keep in the bowl for spreading.

Assemble the Cake:

  1. If the cake has domed, trim the top to level it. Slice the cake horizontally into two even layers using a serrated knife.
  2. Place the bottom layer on a serving plate. Spread a generous layer of chilled taro custard over it.
  3. Place the second cake layer on top. Spread or pipe the whipped cream over the top and sides of the cake.
  4. Optionally, garnish with crumbled taro sponge pieces, edible flowers, fresh fruit, or toasted coconut flakes.

Serve and Store:

  • Chill the assembled cake for 30 minutes to set before serving.
  • Slice and serve chilled for best texture.
  • Store leftovers in an airtight container in the refrigerator for up to 3 days.

Tips:

  • Ensure taro is fully cooked to avoid any raw starch flavor.
  • For a stronger taro flavor, increase taro puree in the custard by 1-2 tablespoons, adjusting milk accordingly.
  • If taro root is unavailable, frozen or powdered taro can be used (reconstitute powder per package instructions).