Preheat oven to 400°; line rimmed baking pan with parchment paper.
In large skillet, melt butter over medium-high heat. Add spinach; cook 2 minutes or until wilted, stirring frequently. Add garlic; cook 1 minute or until fragrant, stirring frequently. Transfer spinach mixture to fine-mesh strainer; with back of spoon, press to remove excess water.
In large bowl, stir cheeses, onion powder, black pepper and spinach mixture. Makes about 2 cups.
Place jalapeños, cut side up, on prepared pan; fill with spinach mixture and sprinkle with breadcrumbs. Wrap 1 piece bacon around each jalapeño; secure with toothpicks. Roast jalapeños 45 minutes or until bacon is crisp and filling is heated through. Makes 16 poppers.
