Preheat the grill to medium-high and prepare for direct grilling.
Heat all of the sauce ingredients except the peanut butter (soy sauce, vinegar, hoisin, sriracha, sesame oil, ginger, optional fish sauce) in a small sauce pan over medium-high just until the mixture begins to come to a simmer. Remove from the heat and stir in the peanut butter until smooth. Set aside.
Brush the zucchini strips with olive oil on both sides, and season with salt and pepper. Lay the strips across the grate, and grill until the strips soften and take on grill marks (2 to 3 minutes). Flip the strips and grill for 1 to 2 minutes more). Remove from the heat and transfer to a cutting board.
Use a very sharp knife or pizza cutter to slice each zucchini strip into "noodles." Divide the noodles between two small-medium bowls. Spoon a generous helping of the peanut sauce over the noodles, and add the pepper dices and scallions. Top with cilantro and chopped peanuts.
*Alternate method: if you have a vegetable grill pan handy, go ahead and julienne the raw zucchini first (this will be especially easy if you have a julienne cutter, a spiralizer, or a mandolin with a julienne blade). Lightly brush the zucchini noodles with olive oil, season with salt and pepper, and grill them in the vegetable pan.