Combine 3 Tbsp of mayonnaise, 3 Tbsp sour cream, 1 Tbsp lemon juice, and 1 pressed garlic clove in a small bowl and set aside.
Season both sides of the salmon fillets with salt and pepper. Then transfer the fish to a rimmed baking sheet lined with foil.
Spread the mayonnaise mixture on top of each fillet.
In a separate bowl, use a fork to combine 1 cup of panko bread crumbs, 1/2 cup Parmesan cheese, 1 Tbsp dried dill, and 3 Tbsp melted butter.
Evenly spread the bread crumb mixture over the mayonnaise on each salmon fillet. Bake at 400 degrees Fahrenheit for 15-20 minutes. Cooking time may vary depending on the thickness of the fillet. Always make sure that your salmon reaches an internal temperature of at leasrt 145 degrees Fahrenhiet.
Serving a crowd- This can be made with a whole salmon fillet instead of small fillet cuts. The bake time will be longer though.
Make-ahead- the mayonnaise mixture can be slathered on hours before topping with the crust and baking.
Bake time- If the salmon is cold out of the fridge, it may take longer to bake.