1. Preheat oven to 350°. Stir together flour and next 5 ingredients in a large bowl. Gradually add oil, beating at medium speed with an electric mixer until blended. Add eggs, 1 at a time, beating until blended. Add buttermilk and vanilla, beating until blended. Fold in preserves and pecans.
2. Spoon batter into 2 lightly greased (12-cup) muffin pans, filling 20 muffin cups about three-fourths full.
3. Bake at 350° for 15 to 18 minutes or until a wooden pick inserted in center comes out clean. Cool in pans 5 minutes. Invert cakes onto wire racks. Cool 15 minutes.
4. Drizzle cakes with Buttermilk Glaze. Cool 10 minutes. Pipe Vanilla Hard Sauce onto warm cakes, and serve.