Step 1: Prepare the Peppers: Preheat your oven to 400°F (200°C) and lightly grease a 9x9 or similar-sized baking dish. Wash the mini bell peppers and pat them dry with paper towels. Cut each pepper in half lengthwise, keeping the stem intact for presentation if desired. Remove the seeds and membranes using a small spoon or knife. Arrange the pepper halves in a single layer in the prepared baking dish, cut side up. Drizzle the peppers with a small amount of olive oil and sprinkle with salt. Use a pastry brush to evenly distribute the oil.
Step 2: Brown the Sausage: In a large skillet over medium heat, cook the Italian sausage until browned and no longer pink, breaking it into small crumbles as it cooks (about a 5-6 minutes).
Step 3: Add Spinach: Add the baby spinach and green onion and allow the spinach to wilt 3-4 minutes, stirring frequently to prevent the delicate spinach from burning.
Step 4: Make the Cream Cheese Filling: In a mixing bowl, combine the softened cream cheese, cooked sausage mixture, shredded cheddar, hot sauce, and seasonings. Mix thoroughly until all ingredients are well incorporated.
Step 5: Stuff the Pepper Shells: Spoon or pipe the cream cheese mixture into each pepper half, mounding the filling. Bake in the preheated oven for 20 minutes until the peppers are slightly tender and the filling is heated through with light golden spots on top. Or air fry at 365°F for about 8-10 minutes until the peppers are tender and the filling is golden. Turn the broiler on for the last 1-2 minutes if you prefer a more browned top (watch carefully to prevent burning).
Step 6: Rest & Serve: Remove from the oven and let cool for 5 minutes. Garnish with fresh herbs if desired, and serve warm.