1.Grease and line base and sides of a 20cm springform pan.
2.In a food processor, pulse biscuits to fine crumbs. Add butter and ginger and mix well. Press firmly over base of pan. Freeze for 10 minutes.
3.In a medium bowl using an electric mixer, beat cream cheese until smooth. Beat in cream, whipped to soft peaks, lemon juice, vanilla bean paste and 1 teaspoon matcha powder until smooth.
4.Sprinkle gelatine over boiled water and whisk vigorously with a fork to dissolve. Beat into cream cheese mixture, then gradually add white chocolate, beating to combine.
5.Pour cream-cheese mixture into pan, reserving 1/3 cup. Whisk extra matcha powder into reserved mixture. Spoon large dollops over cheesecake and gently swirl through, using a butter knife. Chill, covered, 4 hours or overnight. Serve dusted with extra matcha powder.