In a small bowl, whisk together the hoisin sauce, peanut butter, tamari sauce, rice vinegar, sesame oil, garlic cloves and ginger root until smooth. Set aside.
Heat a large skillet over medium-high heat. Add the tofu cubes and cook until lightly browned on all sides, about 5 minutes. Stir in the carrot and bell pepper strips and cook for an additional 2 minutes.
Remove from heat and stir in the green onions and bean sprouts if desired. Pour the hoisin mixture into the pan and stir to combine.
To assemble the spring rolls: Place one wrapper onto a clean work surface. Place 1/4 cup of filling in the center of the wrapper. Fold up bottom corner of wrapper over filling; fold in sides; then roll up tightly.