Preheat oven to 350. Place wire rack in middle of oven. Line a baking sheet with parchment paper
In large bowl, whisk together flour, sugar, baking soda, baking powder and salt. Cut the butter into small pieces and blend into flour mixture with a pastry blender or 2 knifes. The mixture should look like coarse crumbles. Stir in chocolate chunks and raspberries. In a small bowl whisk together yogurt, vanilla and egg. Add this to flour mixture and stir until dough comes together. Do not over mix.
Transfer to a lightly floured surface and knead the dough gently 4 or 5 times and then pat, or roll dough into a circle about 7 inches round. Cut the dough into 8 triangles. Place scones on baking sheet. Brush top of scone with egg wash (1 well beaten egg mixed with 1 tbsp milk)
Bake for 18-20 minutes or until golden brown and toothpick comes out clean.