- Preheat the oven to 350 degrees F. 
- Grease a 9”x5” loaf pan with baking spray and line it with parchment paper, allowing excess paper to overhang the sides of the pan so it can easily be lifted out. 
- In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice. Set aside. 
- In a large bowl using a handheld electric mixer (or stand mixer fitted with a paddle attachment), beat the softened butter with granulated sugar and brown sugar for 3 minutes. 
- Scrape down the sides of the bowl and add the oil, canned pumpkin puree, eggs, vanilla extract, and whole milk. 
- Beat for about 30 seconds or until everything is combined. 
- Carefully add the dry ingredients to the wet ingredients and mix together on a medium speed (or simply with a rubber spatula), scraping down the sides of the bowl as needed. Only mix until all the ingredients are just combined; overmixing can result in a dense cake. 
- Transfer the pumpkin cake batter into the prepared loaf pan and smooth into an even layer. 
- Run a knife down the center of the batter to create a line. This will help the loaf cake rise evenly and have a perfect loaf crack down the center, rather than being lopsided and random. 
- Bake the cake in the center rack of the oven for 55-65 minutes, making sure a toothpick comes out clean to ensure that it's fully baked. 
- Place the cake pan onto a wire cooling rack and allow it to cool for 30 minutes before using the parchment paper overhang to remove the cake from the pan. 
- Allow the cake to cool on the wire rack for at least 1-2 hours (if possible) before icing or serving.