Cake Ingredients

½ lb (2 sticks) unsalted butter, at room temperature
¾ cup superfine sugar
¼ tsp table salt
1 tsp vanilla extract
3 large eggs, at room temperature
3 large egg yolks, at room temperature
1 ½ cups all-purpose flour
½ cup medium-grind yellow cornmeal
1 tsp baking powder

Fruit Ingredients

2 T superfine sugar
2 ripe plums, stoned and cut into 1/8-inch slices
2 ripe nectarines, stoned and cut into 1/8-inch slices
2 cups blackberries

1/3 cup mascarpone mixed with 1 teaspoon superfine sugar, for garnish (sweetened crème fraîche or whipped cream may be substituted for the mascarpone).

Instructions

Preheat the oven to 350°F.  Butter a 9x5-insh loaf pan and dredge it with polenta, shaking out the excess.

Cake:
In a stand mixer or with a strong hand mixer, cream the butter, sugar, and salt together until light and fluffy.  Add the vanilla.  Add the eggs and egg yolks, one at a time, completely incorporating each one before adding the next.  Sift in the flour, polenta, and baking powder and mix well.  Pour the batter into the pan.

Bake for 50 to 55 minutes, or until the top springs back and a skewer inserted in the center comes out clean.  Run a knife around the pan to release the cake and invert it onto a cooling rack.  Allow to cool completely.

Cut the cake into 1-insh slices, place on individual desserts plates and spoon some of the warm fruit and syrup over each (look below for how to prepare the fruit).  Top with a dollop of sweetened mascarpone and serve.

Fruit syrup:
In a medium saucepan, combine the crème de cassis with the apple juice and sugar.  Stir over low heat until the sugar has dissolved.  Increase the heat and bring the mixture to a boil.  Add the plums, nectarines, and blackberries and reduce the heat to a simmer.  Cover and let simmer for 8 to 10 minutes, or until the fruits are tender.  Remove the lid and simmer for 6 to 7 minutes more, stirring occasionally, until the syrup has reduced to coating consistency and the softened fruits are glazed with it.