Place 2 cups flour and sugar in a bowl. Stir.
Add cubed butter and rub it in until it's the size of peas and the flour mixture resembles coarse cornmeal.
Add blueberries and strawberries. Gently stir until well coated with flour.
Stir in buttermilk until the dough is wet and sticky.
Turn out the dough onto a well floured tea towel. You can use a hard surface instead of the tea, but a towel makes turning the dough easier.
Sprinkle flour on top and gently start working it into the dough. Flip the dough using the edge of the tea towel. Add more flour and work it in. Continue flipping and adding sugar until the dough is no longer sticky and holds it shape.
Pat the dough into a 1 inch thick square.. Cut the square into fourths with a sharp knife or pizza cutter. Then, cut each fourth into fourths , yielding 16 biscuits.
Place the biscuits, not touching, on a large baking sheet lined with parchment paper or a baking mat.
Dab a little butter on the top of each biscuits. Sprinkle with raw sugar.
Bake in a 425 preheated oven for 25 minutes or until tops and sides are browned.
Remove from oven and serve warm. Or cold. Or the next day. Biscuits are good anytime.