Heat the oil in a heavy large skillet over medium heat. Add the shallots and garlic and sauté until translucent, about 2 minutes. Add the red pepper flakes and white wine and bring to a simmer. Simmer until the wine reduces by half, about 5 minutes. Add the shrimp and cook just until they are pink, about 2 minutes.
Meanwhile, cook the Penne in a large pot of boiling salted water until just tender but still firm to the bite, stirring occasionally, about 8 to 10 minutes.
Drain the penne Add the Penne and spinach to the skillet. Toss to combine. Season the pasta, to taste, with salt and pepper. Transfer the pasta to a large bowl, sprinkle zest over the pasta and serve.