- Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper. 
- In a medium bowl, combine spinach, artichoke hearts, cream cheese, sour cream, minced garlic, salt, pepper, and red pepper flakes (if using). Mix until well combined. 
- Place the bagel halves on the prepared baking sheet, cut side up. Brush the tops lightly with olive oil. 
- Evenly spreading the spinach-artichoke mixture over each bagel half. 
- Sprinkle the mozzarella and Parmesan cheese over the top. 
- Bake for 12-15 minutes, or until the cheese is melted and bubbly and the bagels are slightly crisp. Sprinkle with poppy seeds (if using). 
- Let them cool slightly before serving. Enjoy warm!