Line a 9" square baking pan with foil and grease the foil.
In a small bowl, combine the graham cracker crumbs, pecans, and butter. Press into prepared pan, set aside.
In a large bowl, beat the cream cheese, sugar, and sour cream until smooth. Add eggs and vanilla; beat on low speed just until combined. Pour over crust. Bake at 325* for 35-40 minutes or until center is almost set. Cool on a wire rack. Freeze overnight.
In a microwave, melt chocolate and shortening; stir until smooth. Cool slightly
Using foil, lift cheesecake out of pan. Gently peel off foil; cut into 1 1/4" squares. Work with a few pieces at a time for dipping; keep remaining squares refrigerated until ready to dip.
Using a toothpick, completely dip squares, one at a time, in melted chocolate, allow excess to drip off. Place on waxed paper-lined baking sheets. Let stand for 20 minutes or until set. Store in an airtight container in the refrigerator or freezer.