1 can orange juice concentrate, slightly thawed (use a sweet one or it might turn out bitter)
1 cup 2% milk
1/2 cup sugar/sweetener, or to taste
1/2 teaspoon vanilla extract
2 cups ice, or to taste
Combine all ingredients, except ice, in a large blender and blend until smooth and creamy, taking care the sugar has dissolved and is well incorporated.
If desired, add a splash more water or more milk.
Add the ice and blend until smooth.