Heat the oven to 425°F.
Put the cream cheese, the cheddar or gouda, and the cilantro in a medium bowl. Season with black pepper, and stir to combine.
Halve each jalapeño lengthwise. Trim off the stem, and scrape out and discard the seeds and veins.
Using a spatula or spoon, fill each jalapeño half completely with cream cheese filling. Transfer the jalapeños to a baking sheet and bake until golden brown, about 20 minutes. Serve warm.
