Place first 3 ingredients in a food processor; process until finely ground. Stir in butter. Press cookie crumb mixture into bottom of an ungreased 9" springform pan. Bake at 350° for 15 minutes.
Meanwhile, beat cream cheese, 1 1/4 cups sugar, and cardamom at medium speed with an electric mixer until smooth. Add 1 1/2 cups sour cream, flour, and vanilla bean paste; beat until blended. Add eggs, 1 at a time, beating just until yellow disappears. Pour batter into baked crust.
Bake at 300° for 1 hour and 15 minutes or until almost set. Immediately run a knife around edge of pan, releasing sides. Let cool on a wire rack 10 minutes.
Meanwhile, place white chocolate in a microwave-safe bowl; microwave at HIGH for 1 minute or until chocolate is soft. Stir until smooth. Whisk in remaining 1 1/4 cups sour cream. Spread white chocolate mixture over warm cheesecake. Let cool completely in pan on wire rack. Cover and chill 8 hours. Remove sides of pan. Garnish cheesecake, if desired.