Combine cookie crumbs, 1/4 cup sugar and butter; blend well. Press into bottom and 2" up the sides of a 9" springform pan; set aside.
In a mixing bowl, beat 1 8oz pkg cream cheese and 1/4 cup sugar until fluffy. Add 1 egg and 1/4 tsp vanilla; blend well. Stir in chocolate and 1/3 cup sour cream. Spoon over crust.
In another bowl, beat second 8oz pkg cream cheese, brown sugar and and flour un til fluffy. Add 1 egg and 1/2 tsp vanilla; blend well. Stir in pecans. Spoon carefully over chocolate layer.
In another bowl, beat remaining 3ozs of cream cheese and remaining sugar until fluffy. Blend in last egg. Stir in remaining sour cream and vanilla. Add alm ond extract. Spoon carefully over pecan layer.
Bake at 325 for about 55 minutes or until center is almost set. Turn off oven and leave cheesecake inside for 30 minutes; open door partway and leave cake in oven another 30 minutes. Remove from oven; cool completely. Refrigerate at l east 8 hours.
CHOCOLATE GLAZE: Combine chocolate and butter in top of a double boiler; cook over simmering wat er until melted. Remove from heat; add remaining ingredients and stir until sm ooth. Remove cheesecake from pan and spread warm glaze on top just before ser ving. Yum!!!!!