Ingredients

CAKE:
Cooking spray
1 tablespoon all-purpose flour
1 (15-ounce) can pumpkin
3/4 cup granulated sugar
3/4 cup packed dark brown sugar
1/2 cup butter, softened
4 large eggs
1 teaspoon vanilla extract
3 cups all-purpose flour (about 13 1/2 ounces)
1 1/2 teaspoons pumpkin pie spice
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
3/4 cup fat-free buttermilk
GLAZE:
1/3 cup fat-free buttermilk
1/4 cup granulated sugar
2 tablespoons butter
2 teaspoons cornstarch
1/8 teaspoon baking soda