Sonic Adds New Brownie Batter Shake Alongside Returning Yellow Cake Batter Shake. Sonic is kicking off summer 2020 with the introduction of the new Brownie Batter Shake alongside last-year’s returning fan-favorite Yellow Cake Batter Shake.

Does Sonic have a brownie milkshake?

The new Brownie Batter Shake is hand-mixed with SONIC’s 100% Real, vanilla Ice Cream with a rich, chocolate brownie batter and the Yellow Cake Batter Shake brings decadent, yellow cake batter to life in a delicious ice cream treat. With two options to choose from, the Cake Batter Shakes hit the spot, every time.

What is in the cake batter shake at Sonic?

Sonic’s Brownie Batter Shake features vanilla ice cream blended with chocolate brownie batter and brownie pieces, while their Yellow Cake Batter Shake takes the same vanilla ice cream but blends it with yellow cake batter instead. Both shakes are finished with whipped topping and a maraschino cherry.