Preheat oven to 350°. Bake pecans in a single layer in a shallow pan 10 to 12 minutes or until toasted and fragrant, stirring halfway through.
Line a 15x10 inch jelly-roll pan with aluminum foil; lightly grease foil. Arrange graham crackers in a single layer in prepared pan, slightly overlapping edges.
Combine sugar, butter, and cream in a medium-size heavy saucepan; bring to a boil over medium heat, stirring occasionally. Remove from heat, and stir in vanilla and pecans. Pour butter mixture over crackers, spreading to coat.
Bake at 350 degrees for 10 - 11 minutes or until lightly browned and bubbly.
Immediately sprinkle with salt, and slide foil from pan onto a wire rack. Cool completely (about 30 minutes). Break into bars.
Chocolate-Pecan-Caramel Bars: Prepare recipe as directed through Step 4. Top warm bars with 1 cup dark chocolate morsels. Let stand 3 minutes, and spread chocolate over bars. Proceed with recipe as directed in Step 5. Chill 20 minutes before serving.