Combine the maple syrup, olive oil, apple cider vinegar, Dijon mustard, finely chopped shallot, and salt in a blender or small food processor. Blend the mixture until it becomes silky smooth and fully emulsified.
Give the dressing a taste and fine-tune the seasoning if needed, adjusting the salt or vinegar to your preference. Add the poppy seeds and pulse once or twice to distribute them evenly throughout the dressing without over-blending.
Use the dressing right away for a fresh burst of flavor, or pour it into an airtight container and refrigerate until ready to serve. Shake or stir before each use.