I am going to attempt to make a duck-shaped Perfect Party Cake as my son's first birthday cake. I don't like buttercream (and he'll never know the difference) -- any other suggestions for filling? I want to keep the lemon/raspberry jam idea. I was thinking something pudding- or custard-like, maybe a lemon-flavored pastry cream? I'm worried it will be too heavy or unwieldy and will cause the layers to slide around or sink. I was also thinking about frosting with whipped cream, tinted yellow and orange for the beak with food coloring. All suggestions are welcome!