Ingredients

   
100g white chocolate (baking quality), chopped
42g unsalted butter, cubed
18g matcha
60g whole milk (2% also works)
3 large eggs (50g without shell), yolks and whites separated
38g sugar (for egg yolks)
20g cake flour
1g kosher salt
38g sugar (for egg whites)
  Confectioners’ sugar for dusting (optional)

Steps

  1. Preheat oven to 350°F. Line a 15cm round cake pan with parchment paper.

  2. Melt white chocolate and butter in a double boiler (bowl over simmering water, not touching). Stir until smooth. Remove from heat carefully — no water or steam in the mixture.

  3. Add matcha to the melted chocolate mixture and stir until no lumps remain. Gradually stir in milk.

  4. Refrigerate or freeze egg whites for 15 minutes until cold.

  5. In a large bowl, whisk egg yolks and 38g sugar vigorously until creamy and pale yellow. Add the matcha chocolate mixture and mix well.

  6. Sift 20g cake flour into the batter. Gently whisk until just incorporated — do not overmix. Add salt and stir.

  7. Whip cold egg whites on medium-low until bubbly and foamy. Gradually add 38g sugar while beating. Increase to high speed and beat until stiff, glossy peaks (about 2 minutes).

  8. Fold one-third of the meringue into the batter and mix well. Fold in another third gently. Add the last third and fold until just combined — don’t deflate the bubbles.

  9. Pour batter into the prepared pan and smooth the surface.

  10. Bake at 350°F for 15 minutes, then reduce to 325°F and bake 20 more minutes. The center will still wobble slightly — this is correct. Do not skewer-test this cake.

  11. Cool completely in the pan on a wire rack, about 4 hours. Can also refrigerate overnight.

  12. Slice and dust with confectioners’ sugar. Microwave chilled slices for 5 seconds for a melt-in-your-mouth texture.

Notes

  • Use baking-quality white chocolate, not candy bars.
  • The inside is intentionally soft and fudgy — don’t overbake.
  • Requires 4 hours cooling time before cutting.
  • Use good quality matcha for vivid color and flavor.
  • Cake flour is required. Homemade: for every 120g AP flour, remove 16g and replace with 16g cornstarch, sifted 3–4 times.
  • Double the recipe for a 20–23cm pan, triple for 25–28cm.
  • Store refrigerated 3 days or frozen 1 month.