Preheat your oven to 325 degrees F. Spray two 8-inch round cake pans with nonstick spray, line the bottom with parchment paper, and spray again. Set aside.
Prepare brownie mix accordig to instructions on the box. Bake at 325 degrees F for about 20 minutes. Let cool completely.
To make the custard filling, whisk together the sweetened condensed milk and water until combined. Stir in the pudding mix and then refrigerate until set, about 5 to 10 minutes.
Using a whisk attachment, beat the heavy whipping cream until stiff peaks form. Fold whipped cream into the pudding mixture.
Place one brownie layer on a cake stand or plate. Cover with half of the pudding mixture and then fresh berries. Repeat with second layer.
Serve immediately or coverate and refrigerate until you're ready to serve.