Preheat the oven to 350°F. Grease and flour a 9x13-inch baking pan.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In a large mixing bowl, cream the softened butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
Gradually add the dry ingredients to the butter mixture, alternating with the buttermilk. Mix until just combined.
In a separate bowl, combine the pumpkin puree, pumpkin pie spice, and chopped pecans. Fold the pumpkin mixture into the batter until evenly distributed.
Gently fold in the chocolate chips.
Pour the batter into the prepared baking pan and smooth the top.
Bake for 35-40 minutes, or until a toothpick inserted in the center comes out clean.
Allow to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.