Preheat the oven to 350 degrees. Lightly grease a donut pan with non stick spray.
In a medium bowl, whisk together the all purpose flour, pumpkin pie spice, baking powder, baking soda, and salt.
2 ¼ cups (281 g) all purpose flour, spooned and leveled, 1 tablespoon ground pumpkin pie spice, 1 ½ teaspoon baking powder, ¼ teaspoon baking soda, ½ teaspoon salt
Add the softened butter and granulated white sugar to a large bowl. Cream together for 2 minutes with an electric mixer.
10 tablespoon (140 g) unsalted butter, softened, 1 ½ cups (300 g) granulated white sugar
Then add in the eggs and vanilla and mix until pale in color and smooth, about 1 minute.
2 eggs, at room temperature, 1 teaspoon vanilla
Next add in the buttermilk and canned pumpkin puree and mix until combined.
½ cup (120 ml) buttermilk, at room temperature, 1 cup (244 g) canned pumpkin puree
Add the dry ingredients to the wet ingredients and mix until combined.
Transfer the donut batter to a piping bag fitted with a large circular tip. Pipe the donut batter into the donut pan, ¾ of the way full.
Bake the donuts for 12-13 minutes, or until a toothpick comes out clean from the centers. Let them cool for 2-3 minutes in the pan and then transfer them to a cooling rack until completely cool.