Soak the rice noodles in a bowl of very warm water for 20-30 minutes until they are flexible but still firm to the bite, then drain and set aside.
In a small bowl, whisk together the tamarind paste, fish sauce, coconut sugar, and lime juice 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 red pepper flakes, sautéing for 30 seconds until fragrant.
Add the shrimp to the skillet and cook for 2 minutes per side until pink and opaque. Push the shrimp to one side of the pan.
Crack the egg into the empty side of the skillet and scramble quickly until just set, then mix it in with the shrimp.
Add the drained noodles and the prepared sauce to the pan, tossing constantly for 2-3 minutes until the noodles absorb the sauce and soften.
Fold in the bean sprouts and green onions, cooking for just 1 minute so the sprouts remain crisp.
Plate the noodles and garnish with crushed peanuts and an extra lime wedge if desired.