1 1/2 c. cookie crumbs
1/2 c. powdered sugar
1/3 c. cocoa
1/3 c. butter, melted

Mix these ingredients together in a bowl. Press firmly onto bottom of a 9-inch springform pan; set aside.

Heat oven to 350 degrees.

In large mixing bowl, beat four 8 oz. packages softened cream cheese until fluffy. Gradually beat in one 14 oz. can sweetened condensed milk until smooth. Add 4 large eggs, 1/3 cup plain flour and 1 tablespoon vanilla. Mix well. Divide batter in half. Add two 1 oz. squares semi-sweet chocolate that has been melted to 1/2 of batter. Mix well and pour into prepared pan. Top with remaining batter.

Bake 50 to 55 minutes or until top springs back when lightly touched. Cool on wire rack. Prepare chocolate glaze by mixing two 1 oz. squares semi-sweet chocolate and 1/4 cup whipping cream in a small saucepan over low heat. Cook and stir until thickened and smooth. Remove from heat, cool. Spread on top of cooled cake. Chill. Remove side of pan. Garnish with white chocolate shavings.