Place all ingredients in a glass and stir to combine.
This makes a large cocktail. For two smaller servings, pour half into another glass.
Add ice if desired. Garnish with orange slices if desired.
If using unflavored vodka, increase the amount of orange soda by 2 ounces (for a total of 6 ounces or 3/4 cup). The cocktail will begin to separate after a few minutes because of the carbonated soda. Just stir to re-combine.