Arrange 11 whole graham crackers on an ungreased 15- x 10-inch jellyroll pan.
Bring butter, sugar, and pecans to a boil in a medium saucepan; boil 2 minutes. Pour mixture on crackers, spreading quickly to cover.
Bake at 300° for 12 minutes. Remove crackers to wax paper to cool. Cut with a knife along perforations.