Step 1

Combine first 3 ingredients: stir well. Firmly press mixture into bottom and 1 inch up sides of a lightly greased 9-inch springform pan. Bake at 325 degrees for 10 minutes. Cool in pan on a wire rack.

Step 2

Beat cream cheese at medium speed with an electric mixer until creamy; gradually add 1-1/4 cups sugar, beating well. Add eggs, 1 at a time, beating after each addition and scraping sides and bottom as needed. Stir in sour cream and vanilla. Pour batter into prepared crust.

Step 3

Bake at 325 degrees for 1 hour and 5 minutes. (Center will not be completely set.) Turn oven off, and partially open oven door; leave cake in oven 1 hour. Cool completely on a wire rack; cover and chill at least 8 hours. Gently run a knife around edge of cheesecake to release sides of pan; carefully remove pan. Transfer cheesecake to a serving plate.

Step 4

Melt 1/4 cup butter in a small heavy saucepan; add chocolate morsels. Stir over low heat just until chocolate melts and mixture blends. Spread warm chocolate mixture over cheesecake; chill 15 minutes.

Step 5

Combine caramel topping and pecans in a small saucepan. Bring to a boil, stirring constantly, over medium heat; boil 2 minutes. Remove from heat, and cool 5 minutes. Spread over chocolate; cool completely. Serve immediately or cover and chill. Let stand at room temperature at least 30 minutes before serving.