Pour 3 cups water into 8-L stockpot fitted with steamer basket. Line bottom of steamer basket with some of the remaining banana leaves. Add tamales, overlapping as necessary to fit; cover with remaining leaves or damp kitchen towel. Cover with lid. Bring water to boil on medium-high heat; simmer on medium-low heat 1 hour or until tamales pull away from leaves, adding more boiling water to pan and adjusting heat as necessary to maintain a gentle boil. Serve tamales topped with salsa.