Preheat the oven to 400 degrees f. Place an oven-safe wire rack (either greased or non-stick) onto a cookie sheet.
Trim the ends of the asparagus. Cut the bacon slices lengthwise to make narrower strips. Wrap each bacon strip tightly around an asparagus stalk, only slightly overlapping the bacon on each stalk. Place seam side down onto the wire rack.
Bake for 5-10 minutes. Use tongs to turn over. In a small bowl, combine maple syrup, mustard and chili flakes, using a silicone basting brush, brush the asparagus bundles with glaze. Bake for 10-15 minutes more, until the bacon is almost crispy. Set the oven to broil, then place under the broiler for 1-2 minutes to crisp up more. Enjoy!