Preheat oven to 350 degrees. Line a rimmed baking sheet with parchment paper or foil for easy cleanup.
In a medium bowl, combine artichoke hearts, cream cheese, Parmesan cheese, mayonnaise, and scallions. Stir until uniformly combined.
Arrange mushrooms on baking sheet. Using a small spoon, fill the insides of the caps with the filling and mound additional filling on top of the mushroom.
In a small bowl, combine breadcrumbs, Italian seasoning, and olive oil. Using your fingers, divide the breadcrumbs among the stuffed mushrooms, pressing the crumbs into the filling.
Bake for 12 to 15 minutes, depending on the size of the mushrooms, until the bread crumbs are golden brown and the filling is heated through. Serve warm.