Heat frozen blueberries, maple syrup, and lemon juice over medium heat for 8-10 minutes or until heated through (to allow the blueberries to soak up the mixture).
Once combined, mash the frozen blueberries into the maple.
Use either an immersion blender or put the entire mixture into an actual blender and blend on low (or pulse) until the blueberries and maple are combined into one chunky sauce.