This recipe is based on one of our favorite drinks in Japan, the espresso Coke from Coffee Elementary School in Tokyo introduced to us by one of our dear friends—and culture king—Eugene Hu. The combination of coffee and cola has been around for awhile in Japan (coffee is an actual flavor of Coca-Cola there, like how we have Cherry Coke in the U.S.). It's acidic and sweet and effervescent, but has that coffee flavor complexity and extra kick. And then you get that smooth mouthfeel from the buttercream topping, which is our twist. It's like an American Coke Float. かんぱい Kanpai!
Fill a glass with the ice and add the cold brew. Slowly pour the cola over the ice. Top with the buttercream topping. Mix before drinking.
Salted Buttercream Topping
Sift the powdered sugar into the bowl of a stand mixer. Add the heavy cream and attach the whisk attachment. Start the mixer on medium-low speed.
While the cream is whipping, melt the butter in a bowl
in the microwave; it shouldn’t take more than 20 or 30
seconds, maybe less. Once the butter is melted, thoroughly combine it with the condensed milk.
Continue whipping the cream, gradually increasing the
speed to medium-high. Whip until the cream thickens and
ripples start forming. Turn the mixer speed back down to
medium-low and slowly add the condensed milk mixture.
Continue mixing until the condensed milk is no longer
visible, and stop the mixer when soft peaks form. In other
words, it will look like whipped cream, but it will be soft, not stiff and fluffy. (Be sure to not overwhip it.)
Store the topping in an airtight container in the refrigerator for up to 7 days.