Preheat oven to 400 °F (204 °C) and prepare a rimmed baking sheet with parchment paper and set aside.
In a medium bowl, mix together panko, parmsean cheese, butter, mayo, dijon mustard, dried basil, parsley, lemon zest, and lemon juice until mixture forms.
Pat dry cod fillets then place them on the prepared baking sheet.
Using your hands, scoop and gently form/press the panko breadcrumb mixture on top of each cod fillet, evenly distributing the mixture amongst the two. It's okay if it falls on the sides of them.
Bake in the middle rack for 10 minutes then move up to the top rack for an additional 1 minute to brown the top.
Remove from oven and let sit for 5-10 minutes before serving.