Preheat oven to 450. Spray baking sheet with non-stick spray
Stir together Bisquick, sugar and buttermilk until a soft dough forms.
Fold in blueberries, gently.
Using a large ice cream scoop (mine holds about 3 tbsp), scoop the dough onto the cookie sheet and bake 9-12 minutes or until golden brown.
Let cool for a few minutes on a wire rack, remove to a serving plate.
Combine powdered sugar and milk and spoon over still warm biscuits.