Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9-inch round cake pan.
In a medium bowl, sift together the flour, baking powder, baking soda and salt. Set aside.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla.
Gradually stir the dry ingredients into the wet ingredients until just blended.
Spread the batter into the prepared pan and arrange the nectarine slices and blackberries on top. Bake in the preheated oven for 40 to 45 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Allow cake to cool for 10 minutes before turning out onto a wire rack to cool completely.
Interesting Facts
Nectarines are a type of stone fruit related to peaches, plums, and apricots.
Blackberries are a type of bramble fruit that are related to raspberries, loganberries and boysenberries.
This cake is perfect for summertime gatherings or special occasions.