Preheat oven to 325°F. Grease and flour the bottom of a 9x5-inch loaf pan.
Soak raising in hot tap water for 10 minutes, or until plump. Drain and set aside.
Meanwhile, in a large bowl cream together sugar with 1/2 cup of butter until smooth. Beat in mashed bananas then eggs, one at a time until well blended. Fold in flour, baking powder, baking soda and salt until just mixed.
Gently stir in pecans and reserved raisings. Pour into prepared pan and bake for 1 hour, or until a toothpick inserted in the center comes out clean. Cool on a wire rack for 10 minutes. Loosen edges with a butter knife and carefully remove from pan; cool completely on wire rack.
Meanwhile, in a small saucepan, melt remaining tablespoon of butter; stir in brown sugar and milk. Bring to a gentle boil and simmer for 2 minutes. Remove from heat. Stir in powdered sugar. Beat until thick. Drizzle over bread before slicing.