Preheat the oven to 180°C.
Mix the flour with the baking powder, then fold in the sugar and lemon zest.
Mix the eggs with the vanilla e oil. Add the lemon juice to the yoghurt, then mix with the egg. Add this mixture to the flour, and combine gently.
Fold in the blackberries and flaked almonds, if used.
Spoon the batter into 4 or 6 silicon bundt cake moulds then put these onto a baking tray.
Bake for about 20-25 minutes in the oven until golden brown and an inserted skewer comes out clean.
Let the cakes cool in the mould for 5 minutes, then turn them out onto a wire rack to cool completely.
When cooled, serve or decorate to your liking.