Make the Red Pepper Butter: Combine softened butter, garlic cloves, lemon juice and zest, fresh herbs, drained roasted red peppers, chili powder, cayenne pepper, and salt in a food processor. Pulse until mostly smooth. You will have extra butter; store it for future use.

Cook the Fettuccine: Boil 8 ounces of uncooked fettuccine according to package directions until al dente. Drain, reserving about 1/2 cup of pasta water.

Sauce the Pasta: Return the cooked fettuccine to the warm pot. Add 2-3 tablespoons of the prepared red pepper butter, a splash of cream (optional, for extra creaminess), and a little of the reserved pasta water. Toss well until the pasta is coated and the sauce is creamy. Add more pasta water if needed to reach desired consistency.

Cook the Shrimp: While the pasta is cooking or saucing, heat a skillet over medium heat. Add 2 tablespoons of the red pepper butter. Once melted, add the 16 ounces of raw shrimp.

Sauté Shrimp: Cook the shrimp for 2-3 minutes per side, until they turn pink and are cooked through. For an even creamier sauce, you can add another tablespoon or two of the red pepper butter and a tiny splash of cream to the hot pan with the shrimp and toss to combine.

Serve: Divide the sauced fettuccine and shrimp among plates. Enjoy this vibrant and delicious meal immediately!