Why pour the cold brew on top instead of mixing it in?
A slow pour over the back of a spoon (or just a careful tilt) sits the cold brew on top of the milk and orange juice base, giving you a layered look you'd recognize from a creamsicle. Stir it before you sip, or sip through the layers. Either works.
What kind of orange juice should I use?
Fresh-squeezed is the move if you have an orange and a juicer. Otherwise, 100% orange juice (not from concentrate) is the next best thing. Skip breakfast cocktails and "orange drinks" because they bring sugar without the citrus brightness, which is what makes this drink land.
Can I use whole milk instead of oat?
Yes. Oat milk is what we recommend because it stays creamy without curdling against the orange juice. Whole milk can work if the juice is well-chilled and you pour it gently, but skim and 2% are more likely to break and read thin against the cold brew.