1Heat oven to 350°F. Grease 9x5-inch loaf pan with shortening; lightly flour. Spread 1/2 cup of the pecans in ungreased shallow pan. Bake 6 to 10 minutes, stirring occasionally, until light brown.
2In medium bowl, beat sour cream, granulated sugar, eggs and vanilla with electric mixer on low speed 2 minutes. Beat in flour, baking powder, baking soda and salt just until blended. Stir in apples and toasted pecans. Spoon batter into pan. Sprinkle with remaining 1 cup pecans; lightly press pecans into batter.
3Bake 1 hour to 1 hour 5 minutes or until toothpick inserted in center comes out clean, covering with foil during last 15 minutes to prevent overbrowning, if necessary. Cool 10 minutes; remove from pan to cooling rack.
4In 1-quart heavy saucepan, heat butter and brown sugar to boiling over medium heat, stirring constantly; boil 1 minute. Spoon glaze over top of bread. Cool completely, about 2 hours.