Preheat the oven: Set your oven to 375°F (190°C). Line a baking sheet or 9x13-inch pan with parchment for easy cleanup.

Prep the zucchini: Slice each zucchini in half lengthwise. Use a spoon to scoop out the soft center, leaving about 1/4-inch walls to form “boats.” Reserve about half of the scooped flesh, chop it, and squeeze out excess moisture with a paper towel.

Season and par-bake: Place the zucchini boats cut side up on the pan. Brush with olive oil and sprinkle with salt and pepper. Bake for 10–12 minutes to soften slightly. This keeps the boats from turning watery later.

Cook the bacon: If you haven’t already, cook the bacon until crisp and crumble it. Set aside. Save a teaspoon of bacon fat if you’d like extra flavor in the filling.

Make the filling: In a large bowl, combine the cream cheese, sour cream, ranch seasoning, and garlic. Stir until smooth. Fold in the chicken, chopped zucchini flesh, half the mozzarella, all the cheddar, most of the bacon (reserve some for topping), and green onions. Taste and add salt, pepper, and red pepper flakes if using.

Fill the boats: Spoon the mixture evenly into the par-baked zucchini. Don’t overpack to the point of spilling, but a generous mound is fine.

Add cheese and bake: Top with the remaining mozzarella and a little extra black pepper. Bake for 15–18 minutes, until the cheese melts and the filling is hot.

Finish under the broiler (optional): For golden, bubbly tops, broil for 1–2 minutes. Watch closely so it doesn’t burn.

Garnish and serve: Sprinkle with reserved bacon and more green onions. Let rest 5 minutes before serving so the filling sets slightly.