Put the brownie mix in a bowl and add the espresso powder. Continue to add the ingredients as listed on the box, and then pour the batter into an 8" or 9" springform pan that has been coated with non-stick spray. Bake according to package directions. Remove from oven and let cool.
Soften the ice cream. (I put it in a metal bowl and set it in the warm oven for a few minutes, then gave it a stir.) I used about ½ of a 1.5-quart size container. There would be room to use more if you like. Spread the ice cream over the brownie, cover with plastic wrap and put in the freezer.
When the ice cream is firm you can mix up the whipped cream. I used 8 ounces of whipping cream and 2 heaping tablespoons of powdered sugar. Whip until fairly thick. You can use a piping bag (or a plastic bag with the corner cut out) and make a decorative design on your cake. I made a simple star. Cover with plastic wrap again, you should have plenty of room and the plastic shouldn't be touching the whipped cream. Return to freezer.
When the whipped topping is firm, release the ring from around the cake. You may need to work with this slowly or rub your hands over the side for a minute to help loosen it. Use the caramel sauce and drizzle over the top.
The brownie cake cut fairly easily as soon as we took it out of the freezer.
So many possibilities with this recipe. Change up the ice cream and topping flavors to your liking. Add colorful sprinkles to brighten it up a bit.