HEAT oven to 325°F. Place 24 paper baking cups in muffin pans.
BEAT eggs, bananas, oil, water and vanilla in large bowl with electric mixer until blended. Add pancake mix, cocoa, sugar and salt. Beat until smooth. Fill baking cups one-half full.
BAKE 18 to 20 minutes or until toothpick inserted in center comes out clean. Remove from pan. Place on rack to cool completely.
BEAT frosting, peanut butter and milk in medium bowl with electric mixer until blended. Spread on cooled cupcakes.