Combine raisins and hot water in a 1-cup glass measuring cup. Let stand 10 minutes. Drain well.
Place pecans in a single layer in a 15- x 10-inch jelly-roll pan.
Bake at 350° for 4 to 6 minutes or until lightly toasted, stirring occasionally. Remove from pan.
Place oats in jelly-roll pan.
Bake at 400° for 5 to 6 minutes or until lightly browned. Cool 15 minutes.
Combine pecans, oats, granulated sugar, and next 4 ingredients.
Cut 1/3 cup buttery spread into oats mixture with a pastry blender or fork until crumbly. Stir together raisins, 3/4 cup buttermilk, and egg. Add to flour mixture, stirring just until dry ingredients are moistened.
Coat jelly-roll pan with cooking spray. Turn dough out onto pan. Shape dough into a 7-inch circle.
Bake at 400° for 15 to 18 minutes or until a wooden pick inserted in center comes out clean. Brush with 1 Tbsp. buttery spread. Let cool 10 minutes.
Stir together powdered sugar and 2 Tbsp. buttermilk until smooth; drizzle over scone. Cut into 8 wedges.