Preheat oven to 350 degrees.
Press pound cake crumbs on bottom of a lightly greased 9 inch springform pan.
Bake for 5 minutes. Remove and cool on wire rack.
Melt white chocolate in a heavy saucepan over low heat, stirring constantly. Cool.
Beat cream cheese at medium speed with an electric mixer 3 minutes or until fluffy.
Add sugar, beat 5 minutes. Add chocolate, beat 5 minutes.
Add sour cream, brandy (if using), and vanilla. Mix until blended.
Pour into prepared crust.
Bake 30-35 minutes. Cool 10 minutes on wire rack.
Gently run a knife around edge of pan to release sides.
Let cool completely in pan on wire rack.
Chill at least 8 hours before serving.