Preheat your oven to 350°F (180°C) and adjust a rack to the upper third position. Line a large baking sheet with aluminum foil and spray it lightly with cooking spray.

Clean the mushrooms gently with a damp paper towel to remove dirt. Trim and discard the tough stems, then finely chop enough stems to make 1 cup.

Heat olive oil in a large skillet over medium heat. Add the minced garlic and chopped mushroom stems. Cook, stirring frequently, for about 3 minutes until any liquid has evaporated. Transfer to a mixing bowl.

To the same bowl, add the cream cheese, shredded cheddar, cooked bacon, scallions, onion soup mix, and black pepper. Mix until the filling is evenly combined.

Use a small spoon or teaspoon measurer to fill each mushroom cap with 1 1/2 teaspoons to 1 tablespoon of the mixture, depending on the size of the mushroom.

In a small bowl, combine the panko and chopped almonds. Gently press the tops of the mushrooms into the topping to coat the filling. Place the mushrooms filling-side up on the prepared baking sheet.

Spray the tops lightly with cooking spray and bake for 15–20 minutes until the mushrooms are tender and the filling is heated through.

Switch your oven to broil and cook for another 1–2 minutes to achieve a perfectly crispy, golden topping. Remove from the oven and garnish with extra scallions. Serve warm.