Preheat the oven to 175° C (350° F).

Combine the yogurt, eggs, sugar, vanilla and oil. In another bowl, sift together the flour and baking powder. Add the flour mixture into the yogurt mixture, and blend together. Pour half of the batter into a ten-inch cake pan (bottom lined with parchment paper, sides greased), then pour half of the raspberries on the surface. Cover the berries with the remaining batter, top with remaining half of the berries.  Shield the edges of the cake with foil (like you do for pie crust).  Bake for 40 to 45 minutes (took us about 60 minutes), until the top is golden brown and a cake tester comes out clean. Let stand for ten minutes, and transfer onto a rack to cool.

Serve with vanilla ice cream or vanilla sauce. The cake is better the next day.