In a blender, combine orange juice concentrate, sugar, milk, vanilla, and ice cubes.
Blend and pulse until completely smooth.
Serve immediately with an orange slice to garnish.
Notes
I know it can be tempting to skip the orange juice concentrate and replace with orange juice, but I think the concentrate is an essential element in this recipe. It’s worth a run to the store if you are thinking of making this recipe!
You can add a little extra vanilla if you are like me and you always add extra vanilla.
If you want to use a whole tube of OJ concentrate, just double this recipe.