Preheat your oven to 400°F (200ºC).
Season both sides of the salmon fillets with kosher salt and black pepper, place in a baking dish, and bake for about 12 minutes until cooked through.
Bring a large pot of salted water to a boil and cook the pappardelle pasta according to package instructions until al dente.
Melt unsalted butter in a medium pot over medium heat, add minced garlic, and sauté for about two minutes until fragrant.
Add heavy cream, grated lemon zest, and dry white grape juice into the pot with garlic, stirring continuously until it thickens slightly.
Add cooked pasta, baby spinach leaves, and capers into the creamy mixture, then gently fold in the baked salmon pieces. Serve immediately.