Liberally grease a large slow cooker with cooking spray. In a large bowl, combine the fudge brownie mix, oil, water, and eggs until combined and glossy. Pour the batter into the prepared slow cooker.
Meanwhile, whisk together the hot water and the jar of hot fudge sauce until smooth. Pour over the brownie batter. Top with the lid and cook on HIGH for 3 to 3.5 hours or until the edges are set. The center will be gooey—this is okay!
Spoon onto a plate or bowl and serve with ice cream and chocolate sauce.
Healthy chocolate brownies
Heat the oven to 190C/170C fan/gas 5 and line a shallow 23cm square baking tin with baking parchment. Tip the beans, cocoa, coffee granules, xylitol, vanilla, eggs and yogurt into a large bowl. Blitz using a hand blender until smooth. Or, do this in a food processor. Add the baking powder, then blitz again.