Drain water from tofu package and wrap the block of tofu with paper towels. Place the tofu on top of a plate, and press it down with something heavy. I usually put a bag of flour or sugar inside a saucepan, then place the saucepan on top of the tofu. Let it sit for 15 minutes.
Place the tofu, green onion, rice vinegar, sesame oil, salt, and garlic powder in a food processor. Blend until the tofu becomes tiny pieces, about the size of couscous.
Chop the carrot in half, and then chop each half into thin matchstick slices. Chop of the ends of the cucumbers and chop it into thin slices.
Take a sheet of sushi seaweed and place it on a sushi rolling mat, shiny side down. Spread some of the tofu mixture onto the seaweed. It should fill about 1/3 to 1/2 of the sheet. Pack the tofu down. Place some carrots and cucumber on top of the tofu and roll. To seal sushi, wet the edge with a tiny bit of water and roll.
Cut the sushi into half-inch pieces by using a very sharp knife. I like to wipe the blade clean between slices.
Serve immediately or refrigerate for a day or two.