Preheat oven to 180 degrees C. Grease and flour a 23cm round cake tin. Sift together the polenta, flour, salt and baking powder; set aside.
In a medium bowl cream together the butter and sugar. Beat in the eggs one at a time then stir in the vanilla. Add the dry ingredients alternately with the yoghurt, stirring after each addition. Finally, fold in the strawberries. Pour the batter into the prepared tin.
Bake for 45 to 50 minutes in the preheated oven until a toothpick or knife inserted comes out clean. Cool cake in the tin on a wire rack for 30 minutes then invert onto a serving plate. Serve with ice cream or whipped cream.