Preheat the oven to 400 degrees. Spray the cavities of (2) donut pans with cooking spray and set aside (these are my favourites).
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In a large bowl, whisk the sugar, eggs and oil for about 1 minute. Then, add the buttermilk, vanilla, lemon zest, lemon juice and whisk until well blended.
Add the dry ingredients to the wet ingredients and stir until just combined, taking care not to over mix.
Pour evenly into the (12) cavities of the prepared donut pans. Sprinkle with granulated sugar (this helps them to crisp up slightly).
Bake for 12-15 minutes or until slightly browned and an inserted toothpick comes out clean.
Cool on a wire rack in the pan for 5 minutes, then remove from the pan and cool completely on the wire rack.
Dust with powdered sugar (here's my favourite sifter - it has a lid!) and enjoy!