In a medium mixing bowl, combine the softened cream cheese, 1/4 cup grated parmesan, 1/2 cup finely chopped fresh spinach, and 1 minced garlic clove. Mix vigorously until it forms a thick paste.

Using a sharp paring knife, slice a deep, horizontal pocket into the thickest side of each salmon fillet. Spoon the cream cheese mixture evenly into the pockets and wipe away any excess.

Whisk together the paprika, garlic powder, onion powder, cayenne pepper, and salt. Pat the salmon dry, then rub the seasoning heavily over the outside to form a thick layer.

Heat olive oil in a dark metal skillet over medium-high heat. Add the salmon and sear undisturbed for 4-5 minutes until a deeply dark blackened crust forms on the bottom.

Gently flip the fillets with a fish spatula and sear the other side for 4 minutes until the fish is opaque and cooked through. Remove the salmon from the pan and set aside.

Reduce heat to medium-low. Melt butter in the skillet and sauté the remaining 2 cloves of minced garlic for 30 seconds. Pour in the heavy cream, scraping up the browned bits, and bring to a simmer.

Whisk in the remaining 1/4 cup parmesan until smooth. Stir in the 2 cups of fresh baby spinach and cook for 60 seconds until perfectly wilted and bubbling around the edges.

Nestle the salmon back into the skillet, resting on the wilted spinach. Garnish with finely chopped parsley and serve immediately from the warm pan.