Once the spinach has thawed, wrap it in a dishtowel, and stand over the sink and squeeze the spinach to drain as much liquid out of it as possible. Set aside.
Place the vegan butter in a saucepan over medium heat. Sauté chopped green onions until tender, 3 to 5 minutes. Reduce heat to medium and add the chopped garlic and cook for another minute or so. Add the spinach, vegan cream cheese, vegan mayo, salt, and pepper. Stir to combine.
Add the tofu to the food processor and pulse until mostly smooth. Add the spinach mixture and pulse several times to combine and break up the spinach into smaller pieces.
Serve this with chips and crackers. This will last in a sealed container in your fridge for up to 5 days or up to 2 months in a freezer.
Make-Ahead Tip: Make this dip a day ahead and then store it in the fridge in a lidded container. Warm before serving.