Raspberry jelly or jam makes a delicious cake filling that incorporates fruit. Use it alone or combine it with ganache, buttercream or pastry cream. Raspberry jelly is an ideal choice for hot weather because it isn't highly perishable and won't melt. A jelly filling also helps keep the cake moist.

To use raspberry jelly as a cake filling, warm it slightly in the microwave to soften it. Strain the jelly through a sieve if it has seeds. Stir the jelly until it's smooth and spreadable, adding a bit of pulp-free orange juice or raspberry liquor, if you like. Before you spread the jelly on a round cake, pipe a bit of buttercream frosting around the outside edges of the cake. This frosting acts as a barrier, keeping the raspberry filling in place and preventing the color from bleeding to the outside edges of the cake.

Choose cake and frosting flavors that complement the taste of raspberry jelly. Raspberry filling has a fresh, bright flavor when paired with lemon or white cake and topped with buttercream frosting. It's absolutely decadent when used in a rich chocolate cake and topped with a chocolate ganache glaze. Combine raspberry filling with an almond flavored cake for a deliciously understated flavor.

When adding a filling to a cake, spread a layer at least 1/8 inch thick, but no more than 1/4 inch thick, over the cake. Store cakes in a cool room and use them within two or three days. If the cake includes a perishable frosting, such as whipped cream, keep it refrigerated.