Preheat oven to 350°F. Bake the pecans in a single layer in a shallow pan 10 to 12 minutes or until toasted and fragrant, stirring halfway through.
Line a 15- x 10-inch jelly-roll pan with parchment paper. Arrange the graham crackers in a single layer in parchment-lined pan, so pieces butt up to one another, completely covering bottom of pan.
Combine the sugar, butter, and cream in a medium-size heavy saucepan; bring to a boil over medium heat, while stirring.
Remove from the heat, and stir in the vanilla and pecans. Pour the butter mixture over the crackers, spreading to coat.
Bake in the preheated oven for 10 to 11 minutes or until lightly browned and bubbly.
Remove from oven and immediately sprinkle with salt. Allow to stand 10 minutes.
Lift edges of parchment paper and remove from pan, transferring onto a wire rack. Cool completely, about 30 minutes.
Cut into serving pieces.
Optional: Melt chocolate chips according to package directions. Transfer melted chocolate to plastic zip top bag, snip end of bag and drizzle with melted chocolate. Allow chocolate to set. Store in airtight container until ready to serve.