Place the brown rice noodles in a bowl of very hot water and soak for 8-10 minutes until tender but firm, then drain and set aside.
In a small jar, whisk together the tamari, fish sauce, lime juice, and maple syrup to create the pad thai sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat, then add the minced garlic and red pepper flakes, sautéing for 30 seconds until fragrant.
Add the shrimp to the skillet and cook for 2-3 minutes per side until they turn pink and opaque, then push them to one side of the pan.
Crack the egg into the empty side of the skillet and scramble it quickly until just set.
Add the soaked noodles, the prepared sauce, and the bean sprouts to the pan, tossing everything together for 1-2 minutes until the noodles are well-coated and the sprouts are slightly softened.
Remove from heat and stir in the sliced green onions.
Serve immediately topped with crushed peanuts and an extra squeeze of fresh lime if desired.