Preheat oven to 350°F.  Spray interiors of jars with cooking spray.  Add 2 tablespoons of pecans to each jar.

Whisk together sugar and flour in a large bowl.  Add corn syrup, evaporated milk and vanilla using a spoon.  Pour a scant 1/4 cup filling into each jar.  Place filled jars on a baking sheet.

Bake on center rack of oven for 25 to 35 minutes.

Cool for 2 hours on wire rack before serving.

Serve each with a dollop of whipped cream.  Garnish with crumbled cookies if desired.

Note:  If using another size jar (other than the 4-ounce size called for), be sure to leave about 3/4-inch between the pecan filling and the rim of the jar to avoid boilovers.