Cook the Pasta:
Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente.
Reserve 1/4 cup of pasta water before draining, then set the pasta aside.
Cook the Salmon:
Season the salmon fillets with salt, black pepper, and garlic powder.
Heat olive oil in a skillet over medium-high heat. Cook the salmon for 3-4 minutes per side, until golden brown and cooked through. Remove from the pan and set aside.
Make the Sauce:
In the same skillet, melt the butter over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant.
Stir in the heavy cream, Parmesan cheese, dill, and red pepper flakes (if using). Cook for 3-4 minutes until the sauce thickens slightly.
Add the reserved pasta water and lemon juice, stirring to combine.
Combine Pasta and Sauce:
Add the cooked pasta to the skillet and toss to coat in the creamy sauce. Flake the cooked salmon into chunks and gently fold it into the pasta.
Serve:
Plate the pasta, garnish with fresh parsley and additional Parmesan cheese, and serve warm.