Use the Sweet Focaccia Dough: here. Then press slices of plum into the top of the dough. Sprinkle with organic granulated sugar. Put the dough in the warm place until it has doubled in size again, about 1 hour. While the dough is rising a second time, preheat the oven to 425 degrees F.
Generously sprinkle the top of the focaccia with some more sugar and lightly drizzle a little more olive oil on top. Bake the dough until the top of the loaf is golden brown, about 30 to 35 minutes. Remove the focaccia from the oven and let it cool before cutting and serving.
*Update 7/26/2013: Adding this recipe to Close to Home's Friday Food Frenzy.*