Prepare the brown rice noodles by soaking them in hot water for 8-10 minutes until tender but firm, then drain and set aside.
In a small bowl, whisk together the tamari, fish sauce, lime juice, coconut sugar, and red pepper flakes to create the pad thai sauce.
Heat the avocado oil in a large wok or skillet over medium-high heat and sauté the minced garlic for 30 seconds until fragrant.
Add the shrimp to the pan and cook for 2-3 minutes until pink and opaque, then push them to one side of the pan.
Crack the egg into the empty side of the pan, scramble it quickly until set, and then mix it with the shrimp.
Add the soaked noodles and the prepared sauce to the pan, tossing everything together for 1-2 minutes until the noodles are well-coated.
Fold in the bean sprouts and scallions, then serve immediately topped with crushed peanuts for a satisfying crunch.