In a small saucepan, add raspberries and half of water. Heat over medium heat until berries are soft.
Strain mixture to remove berries. Place back in saucepan.
Add jello and the rest of the water and stir while heating over medium heat.Heat and stir just until the gelatin is dissolved. You don't want to heat too long or it will change the flavor of the berries.
Remove the mixture from the heat and allow to cool to room temperature.
While berries are cooling, use a mixer to mix heavy cream until it is fluffy.
Fold the berry mixture into the cream mixture until combined well.
Layer bite-sized brownie pieces in the bottom of your single-serve dish, then add raspberry mousse. I use a gallon size freezer bag and snip the corner off to pipe the mousse into the cups.
Keep layering until the the dish is full. You can top with whipped cream and a raspberry.
This makes about 4-6 single serve dishes of brownie raspberry trifle.