If using frozen edamame, cook according to package instructions, then drain and let cool. If using fresh, steam the edamame until tender, about 5 minutes.
In a medium bowl, mash the avocado with a fork until smooth. Stir in the lemon juice, lemon zest, garlic powder, salt, and pepper.
Add the cooked edamame to the avocado mixture and gently fold until combined, leaving some edamame whole for texture.
Toast the whole grain bread slices until golden brown.
Spread the edamame avocado mixture evenly over each slice of toasted bread.
Top with halved cherry tomatoes and sprinkle with chopped cilantro if desired.
Serve immediately and enjoy!