In a small bowl, combine the tamarind paste, fish sauce (or soy sauce), sugar, and chili powder. Stir well until the sugar dissolves. Adjust the flavors to achieve a balanced sweet, sour, salty, and slightly spicy taste. Set the sauce aside.
Soak the rice noodles in warm water for about 20-30 minutes or until they become pliable but not overly soft.
Drain and set aside.
In a wok or large skillet, heat 1 tablespoon of vegetable oil over medium-high heat.
Add the tofu, chicken, shrimp, or your preferred protein (if using) and cook until cooked through. Remove the cooked protein from the pan and set it aside.
In the same pan, add another tablespoon of vegetable oil.
Add the minced garlic and stir-fry for about 30 seconds until fragrant.
Push the garlic to the side of the pan and pour the lightly beaten eggs (if using) into the other side. Scramble the eggs until they're just set.
Add the drained rice noodles to the pan and pour the prepared sauce over them.
Toss everything together to ensure the noodles are well coated with the sauce.
Add the cooked protein (if using), bean sprouts, and half of the chopped green onions. Stir-fry for another 1-2 minutes until everything is heated through.
Transfer the Pad Thai to serving plates.
Sprinkle crushed peanuts over each serving.
Garnish with lime wedges and the remaining chopped green onions.
Optionally, add fresh cilantro leaves for a burst of freshness.
Serve your homemade Pad Thai immediately, allowing diners to squeeze fresh lime juice over their servings for an extra zing of flavor.