1. To prepare topping, combine peaches, 1/3 cup sugar, basil, and juice in a bowl; let stand 1 hour.
2. Preheat oven to 400°.
3. To prepare shortcake, weigh or lightly spoon flour into dry measuring cups, and level with a knife. Combine flour, 7 tablespoons sugar, baking powder, baking soda, and salt in a bowl; stir with a whisk. Cut in butter with a pastry blender or two knives until the mixture resembles coarse meal. Stir in buttermilk with a fork just until combined (do not overmix). Spoon the dough into a 9-inch round metal baking pan coated with cooking spray. Gently brush the dough with milk. Sprinkle with remaining sugar and almonds.
4. Bake at 400° for 23 minutes or until a wooden pick inserted in center comes out clean. Cool 5 minutes in pan on a wire rack. Remove shortcake from pan; cool completely on wire rack.
5. Cut shortcake into 12 wedges. Top each with 1/3 cup peach mixture and 1 tablespoon yogurt.