1. Preheat oven to 350*. In the bowl of a large stand mixer add flour, sugar, baking powder, butter, and milk. Mix on the low setting to combine. You may wish to pause and use a rubber spatula to scrape the sides of the bowl at least once to ensure everything mixes well.
2. Add in the raspberries and walnuts and very gently fold then into the dough by hand or with the spatula. The dough will be sticky so lightly flour your hands first if using that method. Some of the raspberries may burst while mixing them in, this is ok.
3. Turn the dough out onto a well floured surface and shape into a long flattened rectangle. Using a sharp knife and cutting on the diagonal cut 8 triangles.
4. Place the triangles on a baking sheet, spaced at least 2 inches apart, the scones will rise and puff quite a bit during baking.
5. Bake for 20 minutes or until the sones are lightly browned on top. Allow to cool for ten minutes before removing from the baking sheet.