Bring a large pot of salted water to a boil and cook the pasta according to package directions until al dente (about 6–9 minutes). Drain and set aside.
While the pasta cooks, heat a large skillet over medium-high heat. Add the butter and let it melt.
Add the minced garlic and raw shrimp to the skillet, season with salt and pepper, and cook 3–4 minutes until the shrimp turn pink and form a C shape.
Stir in the lime juice and half of the chopped cilantro, then add the cooked pasta and heavy cream. Toss and cook 1–2 minutes more until the sauce thickens and coats the pasta.
Remove from heat, stir in the remaining cilantro, taste and adjust seasoning with salt and pepper, then serve warm.
Instant Pot option: Add pasta, butter, garlic, 1/2 teaspoon salt, and 3 cups water to the Instant Pot. Seal and pressure cook on high for 4 minutes, then quick-release.
After releasing pressure, stir in lime juice, raw shrimp, cilantro, and cream. Use Sauté and cook 3–4 minutes until shrimp are pink, then season to taste and serve.