Adjust oven rack to lower-middle position and heat oven to 400 degrees.
Mix flour, oatmeal, ⅓ cup of sugar, cinnamon, baking powder, salt, baking soda, and raisins in a medium bowl.
Whisk sour cream and egg until smooth. Grate butter into the flour mixture on the large holes of a box grater; toss to combine. Stir in sour cream mixture until large dough clumps form. Use hands to press dough against the bowl into a ball. (There may not seem like enough liquid at first, but as you press, the dough will come together.)
Place on a lightly floured work surface and pat into a 7½-inch circle, about ¾-inch thick. Sprinkle with remaining teaspoon of sugar. Use a sharp knife to cut into 8 triangles; place on a cookie sheet (preferably parchment-lined), about 1 inch apart.
Bake until golden, about 15 to 17 minutes. Cool for 5 minutes and serveāhot, warm, or at room temperature
Recipe by Three Many Cooks at https://threemanycooks.com/recipes/sweet-treats/oatmeal-cinnamon-raisin-scones/