Make sure your ice cream bowl is properly frozen and ready to go.
Prepare the brownies according to the package instructions and let cool.
In a large bowl whisk together the cream and sugar until the sugar is fully dissolved, about 2 minutes. Pour in the eggnog and dash of ground nutmeg and whisk to combine.
Add the eggnog mixture to your ice cream maker and process according to manufacturers instructions, until a soft serve consistency is reached. Pour soft ice cream back into the large bowl.
Cut half of the brownies into small chunks (a little less than 1 inch pieces) and gently fold them into the ice cream, try not to break up the brownie pieces. Save the remaining brownies for later use.
Pour the ice cream into a freezable container (I use a bread loaf pan), and freeze for at least 3 hours or until desired consistency is reached.
Enjoy!