I am making 3 sheet cakes for a wedding and the bride wants seedless raspberry jam as the filling. Is there an easy way to do this? When I make a normal tiered cake I usually do a crumb coat of buttercream so the cake doesn't absorb the jam, but I'm concerned about the logistics of doing it with a sheet cake and not breaking the cake or having it stick to a board as I slide it off. Would there be a better raspberry filling to use instead of the jam? (She likes the taste of the jam--doesn't know what it is--and I could substitute something else.)
Thanks!!

For sheet cake, I would bake two 1.5" high layers for each cake. Spread the jam on the top side of the cake (the part that you trim to make the cake level) and place the other cake top side down. I never put buttercream in with another filling, I've never had a cake soak up the filling, but if you really want both the bc and the jam, that shouldn't be a problem. Anyway by sandwiching together 2 1.5" high layers, you get a nice approx 3" high cake without having to torte.

I just used this raspberry filling on a white cake. It's delicious, and it doesn't soak into the cake so there's no need for a layer of buttercream.

Raspberry Filling
2 12 ounce packages of frozen raspberries (not packed in syrup)
1 1/3 cups water
1 1/2 cups granulated sugar (or to taste.)
2 T of lemon juice (optional)
5-6 T of cornstarch dissolved in 1/2 cup of water

In a saucepan combine the raspberries, water, sugar, and lemon juice. Bring to boil and simmer for 15-20 minutes or until the raspberries have broken down. Remove the mixture from the heat and strain with a fine mesh sieve. Return the stained mixture to the heat. Dissolve the cornstarch in 1/2 cup of water. Whisk the slurry into the raspberry mixture. Bring the mixture back to a boil and simmer for 5 more minutes, stirring occasionally. Remove from heat and cool completely. It will take awhile to set up. It will thicken like a jelly. May stir it for easier spreading on cake.

The recipe for raspberry filling posted above is great...I have used it several time and there is no need to put bc down first.

Since I am "torting" impared I would do the two thinner layers rather than try to tort a sheet cake...

JMHO...

If you are not used to handling big sheet cake and don't want to torte use the injection method. Since you stated it was seedless filling it will work just fine.
Fill a pastry bag w/seedless jam (Or other recipe as long as it is totally smooth); fit bag w/med round tip (like maybe #5); push it into the cake & squeeze in the filling. Do it about every 2" around the cake. Once you have finished place a cake board or pan on the cake and lightly but firmly press down to even out the filling.

If you would like to try torting.... chill the cake; split the layer; using a cake board covered w/Contac Paper, work it between the two pieces of cake; lift off, fill and return top piece. It's not that hard