Preheat oven to 400°F (204°C). Cut 4 bell peppers in half lengthwise, removing seeds and ribs. Set peppers cut side up on a parchment-lined baking sheet and brush all over with 1 Tbsp olive oil. Bake for about 20 minutes, or until they begin to soften. When finished, drain the water out of each pepper and reduce oven temperature to 350°F (176°C).

Meanwhile, microwave 4 cups fresh spinach for 15 to 30 seconds, or until wilted down. Roughly chop, then combine it in a large bowl with all remaining Filling ingredients.

Fill peppers evenly with the ricotta mixture.

In a small bowl, combine ½ cup breadcrumbs and 1 Tbsp oil. Sprinkle this evenly over the peppers.

Return peppers to oven and bake for 30 minutes. If the tops aren't golden brown at this point, turn on the broiler and let them brown, watching closely until they're done (it won't take more than a minute or two!)