Cook noodles according to package directions. Rinse well with cold water to prevent sticking and set aside.

Heat a large skillet over medium heat. Add the smoked sausage in a single layer. Cook on both sides until browned, about 6 minutes total. Remove to a plate.

Add the vegetable oil to the skillet, then the shrimp, green onions, and garlic. Cook 3 to 4 minutes, until shrimp is opaque.

Meanwhile, in a small bowl, whisk together the soy sauce, lime juice, brown sugar, fish sauce, and 2 tablespoons water.

Add the noodles and smoked sausage to the skillet, then the soy mixture. Stir well to combine. Increase heat to medium-high and cook 2 to 3 minutes, or until noodles are hot. Mix in 1/2 of the cilantro and peanuts. Ladle pad Thai into serving bowls and top with remaining cilantro and peanuts.