In a skillet over medium heat, add olive oil and sauté minced garlic until fragrant, about 1 minute.
Add the chopped spinach to the skillet and cook until wilted, approximately 2-3 minutes. Remove from heat.
In a bowl, mix together the cooked spinach, cream cheese, Parmesan cheese, lemon juice, and dried dill (if using). Season with salt and pepper to taste.
Carefully cut a pocket in each salmon fillet by slicing it horizontally, making sure not to cut all the way through.
Stuff each salmon pocket generously with the creamy spinach mixture.
Place the stuffed salmon fillets on a lined baking sheet.
Bake in the preheated oven for 20-25 minutes, or until the salmon is cooked through and flakes easily with a fork.
Garnish with additional dill, if desired, and serve with lemon wedges on the side.