This cake was inspired by Karythopita – a traditional Greek dessert. Karythopita translates as walnut pie, which is is very misleading as there’s no pastry involved. It is actually a rich walnut sheet cake soaked with syrup (usually sugar and honey syrup).
The baking gods must have been smiling on me when I baked this cake because it turned out perfect. The sponge is fluffy, nutty and moist. The yoghurt filling is rich, tangy and not overly sweet. As for the butterscotch sauce… well, words fail me. Lets just say I now want to add it to absolutely everything I bake.
I used 2x15cm/6inch cake tins, but you can use 2x20cm/8inch tins – the layers will simply be a bit thinner. If you wish to make a large celebration cake I would suggest doubling the recipe. Serves 6-8 depending on how generous you are with your slices!
Preheat the oven to 180C Fan |350F . Spray your cake tins with cake release spray.
Grind your walnuts in a food processor until they resemble fine breadcrumbs. Do not over process as they will release oil and you will end up with walnut paste. Combine the walnuts, flour, bicarbonate of soda, salt and spices.
Whisk the egg whites until you get firm peaks, then set aside. Cream the butter, sugar and oil together for 4-5 minutes until light and fluffy. Add the egg yolks one at a time and whisk until they are combined. Add the yoghurt and mix until combined. Add the flour mixture and whisk on low speed until batter is just combined.
Add a spoonful of the egg whites and mix to loosen the batter. Gently fold the remaining egg whites. Divide the batter between the cake tins and level. Bake at the centre of the oven for about 35 minutes until cake is springy on the top and a skewer comes out clean. Cool cakes on a wire rack.
While the cakes are baking, put the sugar and water in a pot. Bring to the boil and then simmer gently until the syrup is slightly reduced (15-20m). Brush a little of the syrup over the cakes – just enough to make the surface moist.
To make the butterscotch sauce, put the butter in a pot and melt over low heat. Tip all the sugar in and stir for 5 minutes until the sugar melts. Add the cream and yoghurt and whisk over medium-low heat for another 5 minutes. Pour the sauce into a measuring jug and cool slightly. Add the vanilla and salt and stir. Taste and adjust the salt/vanilla if needed. Any leftover sauce can be kept in the fridge in an sealed container for up to two weeks.
To make the filling, whisk cold double cream and the icing sugar until you get firm peaks. Gently fold the (cold) yoghurt into the cream. Do not substitute with no fat yoghurt as the filling may become runny.
Spread some butterscotch sauce over the bottom layer of the cake. Top with a generous amount of filling (and more sauce if you like) and repeat with the second layer. Drizzle sauce over the cake and decorate with walnuts (or in this case, pecans – I run out of walnuts!). Keep the cake in the fridge – best consumed within a couple of days.