To an 8 ounce glass add the cold brew concentrate and condensed milk. Mix until combined. Add several scoops of vanilla ice cream (I won’t tell you how to live here. You do you, boo.). Add the seltzer carefully to the side of the glass in a slow and steady stream until you reach the top of the glass. Go in on that situation. Don't even hesitate. Ice cream melts.

Recipe for Iced Coffee Concentrate can be found here.