Arrange graham crackers in a single layer in a foil-lined 15in.x10inx1in baking pan.

In a saucepan, bring butter and brown sugar to boil; cook and stir just until sugar is dissolved.

Remove from heat; add vanilla.

Pour evenly over crackers, sprinkle with pecans.

Bake at 350 for 5 mins. Sprinkle with marshmallows; bake another 3-5 mins longer or until top is bubbly and mallows are lightly browned.

Drizzle with choc. syrup. Cool for 10 mins. Break into squares.