Preheat the oven to 425°F. Line a baking sheet with parchment paper.
Slice the jalapeños in half lengthwise and scoop out the seeds and inner membrane.
Combine the cream cheese, ranch, nutritional yeast, parsley, ¼ cup cheddar cheese, ¼ cup bread crumbs, salt, and pepper in a small bowl.
Fill each pepper with cream cheese filling. Sprinkle with remaining cheddar cheese and breadcrumbs.
For extra crispness, you can spray the filled peppers with olive oil or cooking spray before baking. Bake for 15-20 minutes, until the peppers are soft and the top is golden.