Preheat oven to 400℉ and line a baking sheet with parchment paper or a silicone baking mat. Slice tofu into 1/2-inch strips and place on baking sheet. Bake for 15 minutes, then flip & bake for 15 minutes more. Let cool completely.
Cook the noodles according to the instructions on the package, then rinse under cold water and thoroughly drain. Mix with the butterfly pea tea powder if using and set aside.
Meanwhile, prepare the dipping sauce. Place the peanut butter, lime juice, soy sauce, 2 teaspoons of sriracha, and garlic in a small bowl. Whisk to combine, then slowly drizzle in water until it reaches your desired consistency. Adjust the spice level by adding more sriracha, to taste.
To assemble the spring rolls, fill a shallow dish with water. Dip one sheet of rice paper in, making sure it's fully submerged, for only 10 seconds. It should still feel stiff, as it will continue to soften while you work.
Place the rice paper on a clean cutting board and arrange the fresh herbs in a line down the center. Then, arrange a small amount of the noodles, cabbage, carrots, mango, avocado, and tofu on top, being careful not to overfill.
Fold over the short top and bottom of the rice paper first, holding in the filling, then roll the sides tightly like a burrito. Place with the seam side down on a serving plate and repeat with the remaining ingredients. Keep covered with a lightly moistened paper towel to prevent them from drying out. Serve with dipping sauce on the side.