Preheat the oven to 350°
Spray a doughnut pan with non stick spray and set aside.
In a large bowl whisk together the pumpkin, buttermilk, eggs, sugar, vegetable oil and vanilla until smooth.
In another bowl combine the flour, baking soda, cinnamon, nutmeg and pumpkin pie spice.
Add the dry ingredients to the larger bowl with wet ingredients and stir well until smooth and lump free.
Spoon the batter into each doughnut space or use a piping bag to make sure there is enough batter almost to the top.
Bake in the oven for 12 minutes.
Let sit for 2-3 minutes before turning the pan upside down to extract each doughnut. Transfer to a wire rack.
Mix together the sugar, cinnamon, nutmeg and cardamon.
Toss each doughnut in the cinnamon sugar and serve.