Preheat oven to 350ºF.
Place the pecans in a small baking dish and toast in the oven until lightly browned and fragrant, about 5 minutes. Leave oven on. Coarsley chop the nuts.
Grease and flour a 9-inch square baking pan. In a large bowl, beat the butter and brown sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition. Mix in the pumpkin puree and apples.
In a separate bowl, combine the flour, baking powder, baking soda, cinnamon, nutmeg, ginger, and salt. Then add to the pumpkin mixture. Mix until just blended. Stir in the toasted pecans. Spread the batter in the pan.
Bake until the top is golden and a toothpick inserted in the center comes out clean, 45 to 50 minutes. Let set in pan for 10 minutes, then remove to a wire rack to cool. Dust tops with powdered sugar when completely cool, or frost with cream cheese frosting, below.
Cut into 9 squares before serving.