If frosting seems too soft, add a little bit more powdered sugar.
Just be aware that the consistency could be too soft also because your butter or cream cheese have softened too much (because it’s too hot in the room, or they’ve been out for too long, etc). In that case, cover the bowl with plastic wrap, insert it in the fridge for 5-10 minutes until butter or cream cheese have hardened a little bit. Then, proceed to cream frosting for a few more seconds before using.
I like to brush my cakes with some simple syrup, which is a mixture of equal parts of sugar and water, brought to a boil together and let to cool down. The simple syrup helps to keep the cake moist. I use about 2 or 3 tablespoons of simple syrup per layer.
Pipe a circle of peanut butter frosting on top of the bottom cake layer, along the edge. This will help you keep the jam in the filling without it spilling all over the place.
Fill the cake with a few tablespoons of jelly. Top with next layer. Brush cake with simple syrup. Proceed with the same procedure.
After the cake is filled, it's time to frost it.
To frost the cake, spread a small amount of frosting over the whole cake and smooth it over. place it in the fridge for at least 30 minutes. This is called crumb coating and it's necessary to obtain a smoothly frosted cake, without any crumbs in it.
Continue to frost the cake with the remaining peanut butter cream cheese frosting. Decorate the top with fresh raspberries and chocolate cups if you'd like.