Place a large pot of salted water on to boil for the vermicelli rice noodles. Trim the zucchini and use a peeler to peel it into ribbons. Thinly slice the scallions. Add the zucchini ribbons and sliced scallions to a large bowl. Trim and discard about 1 inch from the bottom of the broccolini.
Grate 1 clove garlic with a microplane. In a medium bowl, mix together the grated garlic, butter, just ½ tsp tamarind paste, just 1 tsp sambal (adding more or less depending on your affinity for heat), and a pinch of salt. Mix the tamarind butter well to combine and chill until you’re ready to serve.
Once the water is boiling, add the vermicelli rice noodles and stir. Turn off the heat and cook until al dente, about 2 to 3 minutes. Drain, rinse with cold water, and drain well again. Add to the large bowl with the zucchini ribbons. Add the hemp seeds and a pinch of salt and pepper. Toss well to combine.
Place a large nonstick skillet over medium-high heat with 1 tbsp vegetable oil. Once hot, add ¼ of the noodle zucchini mixture, pressing into a cake form. Add another noodle cake to the same skillet and cook both, pressing down with a spatula occasionally, until the bottoms have crisped, about 5 to 7 minutes per side. Transfer to a plate and repeat with another 1 tbsp vegetable oil and 2 more cakes.
Return the large pot to medium heat and add the sesame oil. Once the oil is hot, add the broccolini and cook, tossing occasionally, until bright green, about 3 to 4 minutes. Add the edamame, tamari, and ¼ cup water. Cook until the broccolini is tender, about 1 minute more.
Place the scallion zucchini noodle cakes on large plates and top with some of the tamarind butter. Serve with the sautéed broccolini, edamame, and any remaining sambal and tamarind paste.