Preheat the oven to 350 degrees F. Line a baking sheet with parchment paper or a baking mat
Sift together the flour, sugar, baking powder, baking soda, and salt together.
Cut the butter into the flour mixture until it resembles coarse crumbs.
Add the sour cream and mashed bananas to the flour mixture, mix until combined.
Gently fold in the blueberries.
On a lightly floured surface form the dough into a 7-inch circle. With a pizza cutter cut the circle into 8 wedges.
Bake in the preheated oven for 20 to 25 minutes or until the edges of the scones are lightly browned. Remove from the oven and cool on a cooling rack.