Preheat oven to 350 degrees. In a bowl of an electric stand mixer fitted with paddle attachment, combine flour, sugar,butter, baking powder and salt. Mix briefly on low speed to distribute evenly.
In another bowl, whisk together buttercream, cream, egg and vanilla extract. Turn mixer on low speed and slowly pour wet mixture into dry ingredients, increase speed to medium and mix for 1 to 2 minutes, until dough softens. Return to low speed and mix in blueberries until combined. Try not to overmix or dough will turn blue.
With an ice cream scoop or large spoon, drop dough onto parchment-lined baking sheets; you should have 12 scones. Bake for 25 to 35 minutes (less time if berries are fresh). When done, scones should be light brown and firm to the touch, Serve warm or cool.