Preheat your oven to 350?F (175?C). In a medium bowl, mix the flour, baking powder, baking soda, cinnamon, ginger, salt, and nutmeg.

In a mixer bowl, combine the pumpkin, granulated sugar, vegetable oil, and eggs. Beat on low speed until blended. Gradually add the flour mixture, beating until the batter is smooth.

Spread the batter in a greased jelly-roll pan. Bake in the preheated oven for 20 to 25 minutes, or until a wooden pick inserted in the center comes out clean. Let cool completely in the pan on a wire rack.

For the frosting, combine cream cheese, butter, and vanilla in a mixer bowl; beat until smooth. Gradually add powdered sugar, beating until light and fluffy.

Frost the cooled pumpkin bars and garnish with toasted pecans. Cut into 40 squares, about 2 x 2 inches each.