Gather all ingredients and equipment.
In a small bowl, make the dressing by combining soy sauce, vinegar, sesame oil, garlic, ginger, sugar, and red pepper flakes. Set aside.
Cut cucumbers crosswise in half, then cut lengthwise in half to create 8 pieces roughly 4 inches long.
On your cutting board, place a cucumber piece cut side down. Lay the blade of the knife flat on top of the cucumber. Using the heel of your other hand, press down to smash the cucumber and crack the skin. The flesh will begin to break, seperating the seeds.
Repeat on all cucumber pieces. Once smashed, break or slice diagonally into bite size pieces.
In a medium bowl, toss the cucumbers with the dressing.
Top with toasted peanuts and cilantro to serve.
