I made a thinner layer of cake, more like a torte, for a lighter dessert. If you want a larger cake you can double the ganache and do a layer of ganache and raspberries in between the cake layers.
This is a recipe I started making as a teenager for my family. It originally came from a cookbook of my Mom's. I have slightly adapted the recipe over time.
The name buckle comes from the process of the cake batter rising but the berries and topping weighing it down or causing it to "buckle".