Preheat oven to 350°F. Cut and peel the carton off of one quart container of ice cream. Turn it onto a cutting board. Set it on it's side and use a sharp knife to slice squares of ice cream to desired thickness.
Spray the bottom and sides of 2 9x13-inch pans with cooking spray; line with parchment paper that extends up and over the sides. Set aside.
Melt chocolate and butter over medium low heat until just barely melted, stirring occasionally to prevent burning.
Pour into a large bowl and whisk in sugars until smooth. Whisk in eggs, one at a time, until fully incorporated. Whisk in vanilla.
In a separate bowl combine flour, cocoa powder, salt, and espresso powder. Add to the chocolate mixture and gently fold until no streaks of flour remain.
Divide batter evenly between prepared pans and use an offset spatula or knife to level the tops. The batter will be thin and may not reach the edges of the pans.
Bake 12 minutes or until a toothpick inserted into the center comes out with a few crumbs remaining. Do not overbake!! Cool completely in pan.
Remove cooled brownies from the pan and trim the edges with a sharp knife. Cut brownies into individual squares (I did 2-inch squares), and transfer to a parchment-lined baking sheet. Freeze 20 minutes.
Meanwhile, cut and peel the carton off of a one-quart container of ice cream. Transfer to a cutting board and set it on it's side. Use a sharp knife to slice ice cream to desired thickness.
Use a brownie square for reference and cut ice cream into squares (the same size as the brownies). Set each ice cream square on top of a chilled brownie square, and top with a second square.
Press together gently and freeze 2 hours.
