Preheat oven to 350°F (177°C). Spray donut pan with non-stick spray and set aside.

In a large bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and pumpkin pie spice.

In a medium bowl, whisk the oil, brown sugar, eggs, pumpkin puree, milk, and vanilla extract until combined.

Pour the wet ingredients into the dry ingredients and fold together gently until combined and no flour pockets remain.

Spoon batter into the donut cavities using a large zipped-top bag for ease; fill about halfway.

Bake for 10-11 minutes or until the edges and tops are lightly browned. Cool donuts in the pan for 2 minutes before transferring to a wire rack. Re-grease the pan and bake remaining batter.

To make the icing, combine the brown sugar, milk, and butter in a medium saucepan over medium heat, stirring until smooth. Bring to a simmer and allow to simmer for 1 minute.

Remove from heat and whisk in the vanilla extract and sifted confectioners’ sugar until smooth. Taste and add a pinch of salt if desired. Let cool for 5 minutes to thicken.

Dip the tops of the donuts into the warm icing, adding more milk or warming as needed. Place dipped donuts on a wire rack over a baking sheet to let excess icing drip off.