Crust: Mix biscuit crumbs and melted butter. Press firmly into a 6-inch mold. Chill.
Matcha Base: Melt white chocolate and matcha powder together. Mix with softened cream cheese until uniform.
Custard: In a pot, whisk yolks, sugar, and milk. Cook on low heat until thickened. Add soaked gelatin and stir to dissolve.
Combine: Strain the hot custard into the matcha-cheese mixture. Whisk well.
Finish Batter: Add liquid heavy cream. Stir until smooth. Strain the entire batter to ensure no lumps.
Chill: Pour into the mold. Refrigerate for 4+ hours.
Serve: Unmold carefully with a warm towel or hairdryer. Dust with matcha powder.