1. Mix the milk, cake mix, cream cheese and sugar together with a mixer. Mix until smooth.
2. Add the Cool Whip and mix until combined.
3. Add the sprinkles and brownies (you can use store-bought or homemade brownies) and mix until combined.
4. Stir in the chocolate sundae syrup. Stirring a little less will give more of a ribbon of chocolate to the ice cream. Stirring more will make it more uniformly chocolatey.
5. Scoop into a freezable container and freeze.