This Boston Cream Pie has four components: The cake,the
custard filling, the chocolate frosting, and the toasted almonds. All
of them need to be made, then cooled completely before assembling. You can always make all the parts the night before, then assemble
the cake the next day. If you do that, just bring the chocolate
frosting up to room temperature before coating the cake to loosen it up
a little. Once the cake is assembled, plan enough time to chill it for an hour or two before serving.