Gather your ingredients
Preheat your oven to 375°F.
Place a parchment sheet and line your baking pan.
Clean your mushroom with a damp paper towel to wipe off any debris.
Core out your stems and gills. Chop and add to a large bowl.
Place your mushrooms on the sheet pan top down and ready to fill (set aside.)
In the same large bowl that you set your mushroom stems and gills in, place your mayo, cream cheese, parmesan cheese, garlic, green onions, seasonings, herbs and combine well.
Now add your Colossal Crab and fold into mixture gently so as to not break up the crab.
In a small skillet, melt your butter
add your panko and toast slightly to combine.
Using a scooper fill your mushrooms.
Top with buttered Panko crumbs.
Place in your oven on the middle shelf.
Bake for about 18 minutes until golden brown.
Enjoy!