1Preheat oven to 350. In a small bowl combine brown sugar, butter, and cornstarch.
Drain pears, reserving 3 tablespoons of the syrup. Stir reserved syrup into brown sugar mixture. pour mixture into a 13x9x2 inch baking pan. If desired, cut pear halves into fans by making 3-4 lengthwise cuts 1/4 inch from stem end to base end of pear. Arrange whole or fanned pear halves on the syrup in pan, cored sides down.
Sprinkle pecans evenly in pan.
2Prepare cake mix according to package directions, except decrease oil to 2 tablespoons and add pumpkin.
Slowly pour cake batter into pan, spreading evenly.
3Bake 35 to 40 minutes or until a wooden toothpick inserted near center comes out clean. Cool in pan on a wire rack for 5 minutes. Run a thin metal spatula around edges of cake. Carefully, invert cake into a 15x10x1 inch baking pan or onto a very large serving platter with slightly raised sides. Cool about 30 minutes before serving. Serve warm.