Preheat the oven and prepare the baking pan.

In a mixing bowl, cream together the butter and sugar until light and fluffy.

Beat in the eggs one at a time, then stir in the vanilla extract.

In another bowl, combine the flour, baking powder, and salt.

Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Fold in the mixed berries, banana, kiwi, and peach.

Pour the batter into the prepared pan and smooth the top.

Bake in the oven for 30 minutes or until a toothpick comes out clean.

While the cake is baking, whip the heavy cream with the powdered sugar and vanilla extract until soft peaks form.

Once the cake has cooled, top with whipped cream and additional fruit if desired.