1Heat oven to 350°F. Grease bottom only of loaf pan, 9x5x3 inches, with shortening.
2Beat 1/2 cup shortening and the sugar in large bowl with electric mixer on medium speed until fluffy. Beat in eggs and bananas until smooth. Beat in flour, baking powder, baking soda and salt just until mixed. Stir in peanuts and chocolate chips. Pour into pan.
3Bake 1 hour to 1 hour 10 minutes or until toothpick inserted in center comes out clean. Cool in pan 10 minutes; remove from pan to wire rack. Cool completely, about 1 hour.
4Place frosting in small plastic food-storage bag. Microwave on High 6 to 10 seconds or until pourable. Add peanut butter to bag; gently squeeze bag until peanut butter and frosting are well blended. Cut off tiny corner of bag. Squeeze bag to drizzle chocolate mixture over bread.