Cream the butter and sugar until smooth.
Add the eggs in 2-3 batches, mixing well after each addition.
Add the yogurt and mix evenly.
Sift the cake flour and baking powder in, and gently fold together.
Pour the batter into the mold and smooth the top.
Bake in a preheated oven at 180°C (356°F) for 35–40 minutes.
Let cool, then remove from the mold.