Place the ice cubes, blue raspberry syrup, and blue raspberry juice into the blender.
Start blending on low speed, gradually increasing to high, until the mixture is shaved and becomes thick, smooth, and slushy, about 30-40 seconds.
Pause briefly to check the texture, and blend again if necessary until the mixture is evenly blended and has a vibrant blue color.
Pour into glasses, using a spoon if needed to serve the thickest parts.
Optionally, garnish with a few extra ice chips or berries for presentation.
Enjoy immediately with a straw or spoon for a cooling, fruity treat.