Pour 6 oz frozen orange juice concentrate into blender
Add 1 1/2 cups whole milk
Add 1/4 cup granulated sugar
Pour in 2 teaspoons vanilla extract
Blend on high speed for 30 seconds until sugar dissolves
Add 10 ice cubes one at a time while blending
Continue blending for 1-2 minutes until frothy
Check consistency - add remaining ice cubes if needed
Blend until completely smooth with no ice chunks
Pour immediately into glasses and serve
Optional: Garnish with orange slice, whipped cream, or zest