Crust: Place cookies in food processor fitted with metal blade and process into uniform crumbs. Add butter and mix until well combined. Or, mix crumbs and butter in bowl until blended. Pour into 10" springform pan. Press evenly over bottom and about 2/3 up sides. Set aside in refrigerator.

Melt chocolate and peanut butter chips in top of double boiler over simmering water. Slowly add cream. Stir until smooth and chips are melted. Pour into the crust-lined pan and spread within 1/2" of the sides. Place back into the refrigerator until the filling is prepared.

Filling: Beat cream cheese and sugar in large bowl with electric mixer on medium speed until mixture is light and fluffy, about 3 minutes, stopping to scrape down sides of bowl and beaters once or twice. Add peanut butter and mix until incorporated. Beat in eggs and egg white one at a time, stopping to scrape down sides of bowl and beaters several times. Add sour cream, lemon juice and chocolate chips and m, ix until incorporated. Pour into prepared pan.

Place on baking sheet. Bake in a 325 degree oven 55 to 65 minutes or until sides are firm and center jiggles slightly. Remove to wire rack and cool in draft-free place 15 minutes. Increase oven temperature to 350 degrees.

Topping: While cake cools, melt chocolate chips in top of double boiler over simmering water. Remove from heat. Add sour cream and sugar, stirring until smooth. Spread evenly over top of cake. Bake in 350 degree oven for 10 minutes. Cool to room temperature. Cover with plastic wrap. Refrigerate at least 6 hours or until chilled. Before serving, remove sides of springform.

*Note* If desired, the cake may be refrigerated up to 3 days, pr frozen in springform pan covered with plastic wrap and foil. Defrost frozen cake in refrigerator overnight.

(Don Thomas) On Wed, 22 Mar 95 015229 Gmt