Ingredients

   
225g unsalted butter
225g white chocolate, chopped
36g matcha powder (or 42g for stronger flavor)
200g confectioners’ sugar
100g light brown sugar
4 large eggs, room temperature
5g salt
120g all-purpose flour

Steps

  1. Preheat oven to 325°F. Line an 8-inch square pan with parchment paper.

  2. Brown the butter: melt in a light-colored pan over medium heat, stirring occasionally, until amber with dark golden milk solids, about 8–10 minutes. Remove from heat and cool 3 minutes.

  3. Pour warm brown butter over chopped white chocolate. Stir until melted and smooth.

  4. Sift in matcha. Whisk until evenly blended and glossy.

  5. Add both sugars and stir until fully dissolved and the mixture is glossy and smooth.

  6. Add eggs. Break yolks and mix gently until incorporated — do not whip.

  7. Add salt. Sift in flour and fold with a spatula until just combined.

  8. Pour into prepared pan, smooth the top, and drop pan on counter from 7cm to release air pockets.

  9. Bake 45–50 minutes until a toothpick comes out with moist crumbs. Cool in pan at least 1 hour before cutting.

Analysis

Total batter weight: 1111g

Component Amount %
Structure solids (flour) 120g 10.8%
Fat (butter, white chocolate, egg) 304g 27.4%
Sugar (confectioners’ + brown + white chocolate) 386g 34.7%
Liquid (butter water, egg water) 226g 20.3%
Egg/protein 26g 2.3%

Fudgy and rich, on the sweeter side: fat at ~27% and structure at only ~11% make for a dense, gooey set. White chocolate gives no cocoa solids, so flour alone carries structure (hence less of it than the cocoa-laden chocolate version) while the white chocolate pushes sugar up to ~35%. The 36g matcha (~3%) is an inert solid that colors and cuts the sweetness, not structure.

Notes

  • Brown butter is what makes these special — nutty depth and chewier texture. Don’t skip it.
  • Cool the brown butter 3 minutes before adding to white chocolate. Too hot and the chocolate will seize.
  • Dissolving the sugars into the warm mixture is what creates the shiny, crackly top.
  • Don’t whip the eggs — too much air prevents the crackly crust.
  • Use good white chocolate with real cocoa butter (ivory colored, not bright white).
  • Slightly underbaking keeps the center fudgy.
  • Store room temp 1–2 days, refrigerated up to 5 days. Let come to room temp before eating.