best way to make fruit fillings? gelatin? cornstarch?

What I've been doing for my berry fillings lately is cooking about 2 cups of berries with 2-4 tbsp of sugar (depending on how sweet the fruit is) and about 1/2 cup of water. I cook this until the berries break down then I strain out the seeds(I purée strawberries, then strain), then I mix in a packet of jello, usually in the same flavor. Let it cool until it sets, stir to break it up before using. It sets up really well and doesn't bleed into the cake or though buttercream.

This is really good by itself as a filling, mixed with whipped cream, I've even used it to be the sauce on a fruit pizza. I hope this helps.

Fruit filling from K8

 

I make one by cooking strawberries, blueberries, raspberries and blackberries in a heavy sauce pan with a peeled diced granny smith apple and one third cup of sugar and a squirt of lemon juice and simmer gently stirring often for about 30-45 mins

 

But you can use any single berry or any combination. And they can be fresh, frozen or a combination

 

And the pectin in the apple is what sets it--it's really cool--I feel at my pastry chefinest when I make this

Optional--if you cook it shorter or want insurance you can add in a little mixture of 1 tablespoon of cornstarch and 2 tablespoons of water poured into bubbling fruit stuff stirring constantly for another two minutes.

Cool, puree in food processor and then strain out the seeds. Add almond extract if you want. Be sure to securely seal the edges of the filling with buttercream.
 

Then I often mix in some lemon cream (it's super zipped up lemon curd)

The fresh bursting taste is well worth the little bit extra effort. Enough for a quarter sheet.

That sounds great K8memphis...I am going to try it!

cool--you wanna get a tart apple like the granny smith--more pectin

 

and what i do is when i'm trying to determine if it's finished cooking--i take out a small bit and see if it separates when it cools & i tip the plate

 

but if you use the cornstarch  you're fine

 

but the apple thing really works & it's pretty cool