In a large skillet, over medium heat, cook the garlic in 2 tablespoons of the olive oil until golden, about 5 minutes. Add the red pepper flakes and anchovies and cook until the anchovies are dissolved, about 1 minute. Add the edamame and broth. Increase heat to medium-high and simmer until the edamame are tender and the broth is reduced by half, about 15 minutes.
Meanwhile, bring a large pot of lightly salted water to a boil. Cook the linguine according to package directions; drain and add to the skillet. Toss over medium-high heat until well coated, about 2 minutes. Remove from heat. Stir in the parsley and the remaining olive oil. Sprinkle with the cheese, if desired.