Mix the brownie mix and butter together.

Pour out onto a parchment paper covered 16.5 x 11 baking sheet. Cover with another slip of parchment paper. Using a roller, roll out to an even rectangle.

Place in the freezer for 2-4 hours or until hard.

Score and cut the brownie layer in half with a sharp knife.

Spread the softened ice cream on one half, place the other half of the brownie layer on top and put back in the freezer until hardened (2-4 hours). It helps to contain the ice cream within the boundaries if you use the parchment paper folded up as the edges.

Score and cut into squares and eat (or place in plastic or more parchment paper and place back in the freezer for later).