Microwave the brownie mix for 2 to 3 minutes until it reaches 160 degrees. Let it cool before using
Whisk together the milk, cream, sugar, brownie mix, and vanilla until the sugar is dissolved and there are no lumps of mix.
If using an ice cream maker
Follow directions of maker. It's usually place in the bowl of the maker that has been frozen for at least 24 hours, start, and churn for 20-30 minutes until soft serve consistency. Place in a freezer safe container with a lid, cover and freeze for 2-3 hours before serving.
For the no maker directions
Place the liquid in a deep freezer safe container.
Freeze for 1 hour. Remove from freezer and blend well with a whisk or wooden spoon.
Repeat the blending process every 30 minutes for 2-3 hours until a soft serve consistency.
Place in a freezer safe container with a lid, cover and freeze until desired consistency.