Place the brown rice noodles in a bowl of very hot water and soak for 15-20 minutes until softened but still firm, then drain and set aside.
In a small bowl, whisk together the tamari, lime juice, coconut sugar, and red pepper flakes to create the Pad Thai sauce.
Heat the avocado oil in a large skillet or wok over medium-high heat, add the minced garlic, and sauté for 30 seconds until fragrant.
Add the shrimp to the skillet and cook for 2 minutes per side until pink and opaque, then push them to one side of the pan.
Crack the egg into the empty side of the skillet, scramble it until fully cooked, and then mix it into the shrimp.
Add the drained noodles and the prepared sauce to the skillet, tossing constantly for 2 minutes until the noodles are well-coated and tender.
Fold in the bean sprouts and sliced green onions, cooking for just 1 minute more to maintain their crunch.
Serve immediately topped with crushed peanuts and fresh cilantro.