Pre-heat your oven to 180C. Grease 2 x 20cm sandwich tins with a little butter. Now line them both with baking parchment. It is worth doing this, they come away so much easier. I make little circles for the bottom (trace the tins) and then cut long strips for the diameter.
To make the sponges, mix all your ingredients together in a bowl (apart from the apple). I use an electric whisk but a hand whisk is fine.
Peel, core and dice your apple. Toss in a little sugar to sweeten, as Bramley is quite a sour variety, and gently fold into the sponge mix. Divide mixture between two tins. Bake for about 20-25 minutes on 180C. To test whether they are done, poke a skewer into the middle and if it comes out clean, it's ready to come out. Let the sponges cool a little in their tins before carefully taking them out and peeling the parchment away. Now allow them to cool completely on a wire rack. It's fine to make the sponges the night before they are needed. Wrap in foil and put in a cool dark place like a bread bin.
To make your compote, tip the berries and sugar into a saucepan. Let it come to the boil, gently. Cook on a low heat for about 20 minutes, or until the fruit has broken down a little but it's still recognisable. Let it cool. Again, I do this in advance.
Make your cream filling just before you are ready to finish the cake. Whip cream until forming stiff-ish peaks (don't over whip, it's so easy to do - stop when you see silken peaks forming when you lift out the whisk). Now fold in thick Greek yoghurt and maple syrup.
To build the cake, put one sandwich on a plate, and spoon on some compote, spreading so it's right up the sides. Using a palette knife or similar, smooth on the cream filling. Now add more compote. Top with remaining sandwich. I usually choose to show the flattest side on top. Dust with icing sugar. Devour with good friends and gallons of tea.