1. Cook pasta in a large pot of boiling salted water until tender to the bite, 9 to 12 minutes or according to package instructions.
2. Drain and set aside.
3. Meanwhile, toss shrimp with 2 tablespoons olive oil, onion, garlic, 3/4 teaspoons salt, chile flakes, and cumin; marinate at room temperature 10 minutes.
4. Preheat a medium frying pan over medium heat, then add shrimp and marinade.
5. Cook, stirring often, until shrimp are pink and firm, 3 to 4 minutes.
6. In a large bowl, toss together pasta, shrimp mixture, spinach, chickpeas, yogurt, mint, lemon juice, remaining oil, and lemon zest.
7. Season to taste with salt.
8. Serve warm or at room temperature.