Cut each leaf into a roughly 12"x 14" rectangle, then cut scraps into 12 thin ribbons for tying; set aside. Combine coconut cream, sugar, 1⁄4 cup water, and salt in a 12" nonstick skillet over medium-high heat. Cook, stirring, until it begins to bubble, about 2 minutes. Add rice; cook, stirring often, until most of the liquid is absorbed, about 7 minutes. Remove from heat; let rice absorb liquid, about 20 minutes. Divide rice into 12 equal portions.
Working with 1 banana leaf at a time, arrange leaf with a short edge parallel to you, smooth side up. Put a portion of rice in center; top with a banana quarter; press gently. Shape rice into a rectangle. Fold leaf ends over rice to make a packet. Tie with a ribbon. Repeat to make 12 packets in all.
Pour water into a wide-bottomed pot to a depth of 1". Set a colander inside pot. Working in 2 batches, steam packets until firm, about 15 minutes.