Position a rack in the center of the oven and heat the oven to 350 degrees F. Put the couscous in a 9x13-inch baking dish; set aside.

In a small saucepan, heat the chicken broth, butter, saffron, and 1 teaspoon salt over medium-high heat until the butter is melted and the broth is hot. Pour the mixture over the couscous and mix well.

Cover the baking dish with foil and bake until the liquid has been absorbed by the couscous, 10 to 12 minutes. Let sit at room temperature, covered, for 5 minutes. Drizzle the olive oil over the couscous. Using a fork or your fingers, gently mix to coat the couscous in oil and break apart any clumps. Transfer to a serving dish. If not serving immediately, loosely cover the dish and keep warm for up to 30 minutes.