In a mixer, whip heavy cream on high for about 1 minutes or until it thickens up. Remove from mixing bowl.
Add in your cream cheese, sour cream and horseradish to your mixer and blend well.
Add your whipped cream back into the bowl and mix it together gently. You want the whipped cream to remain fluffy.
Pour into your brain mold and place a piece of plastic wrap directly over the cheese dip. It's okay if the brain mold is not full. It will still turn out nice.
Place mold in the fridge overnight to allow it to firm up.
Remove plastic wrap and place upside down onto serving platter.
Add your red pepper jelly to a small bowl along with a 2-3 tablespoons of water. This will thin it out a bit so you can pour it over your brain. Do not add too much water. You want it JUST thin enough to drip over the cheese.
Serve with crackers.
The mold I used holds 48 oz. so it is pretty large. I did not fill my mold all the way to the top. You can use any size mold for your dip. The larger it is, the longer you will want to chill it.