Snap each corn cob in half to make them easier to handle.
Slice the corn kernels off the cobs; add the cobs to a large pot, along with the white parts of the scallions.
Add 5 cups of water to the pot: bring to a boil over medium-high heat; cover, reduce heat to medium-low; simmer for 8 to 10 minutes.
Uncover and discard the cobs.
Add the noodle blocks to the water and, using chopsticks or tongs, turn the noodles until they loosen up; cook until most of the water has been absorbed; 2 to 2-½ minutes.
Reduce heat to medium-low; add the corn kernels, soy sauce and butter; toss for 1 to 2 minutes, until the noodles are tender and the corn is barely cooked and still sweet.
Divide among bowls; top with the scallion greens and serve immediately.
