Prepare brownie batter using the mix, eggs, oil, and water, then bake in a lined pan until set and allow to cool completely
Cut the brownies into a layer that fits your springform pan or leave as a base layer
Place the brownie layer at the bottom of the pan, pressing gently to create an even base
Soften the ice cream slightly, then spread half of it evenly over the brownie layer
Drizzle a layer of chocolate fudge sauce and sprinkle chocolate chips or brownie chunks
Add the remaining ice cream layer and smooth the top
Cover tightly and freeze for at least 4–6 hours until firm
Remove from freezer, let sit for a few minutes, then top with whipped cream and extra fudge before serving