Preheat oven to 350°F (177°C). Grease donut pans with nonstick spray.
In a stand mixer, beat butter, sugar, salt, and vanilla until fluffy.
In a separate bowl, mix flours, baking soda, and baking powder.
Add eggs to mixer, blend until smooth.
Alternate adding flour mixture and buttermilk to mixer, mix well.
Gently fold in blueberries until evenly mixed.
Fill piping bag with batter, pipe into donut wells.
Bake for 18-20 minutes until springy. Cool before glazing.