Preheat the oven to 350°F and lightly spray an 8x8-inch baking dish with nonstick cooking spray.
In a large bowl, combine the oats, baking powder, pumpkin pie spice, and salt.
In another bowl, combine the brown sugar, milk, pumpkin, vanilla extract, and eggs. Mix well.
Stir the wet mixture into the dry just enough to get it moistened. Fold in the pecans, reserving a tablespoon or so for the top. Pour the mixture into the prepared baking dish and sprinkle with the reserved pecans. Bake for 35 to 40 minutes or until golden brown and set.