Meanwhile, in a medium bowl, whisk together the cake flour, baking powder and 1/2 teaspoon salt. Using a hand held mixer, beat the sugar and eggs at high speed until pale yellow and fluffy, about 5 min. At low speed, mix in half of the dry ingredients, 1/2 cup at a time. Gradually mix in the melted butter, then the remaining dry ingredients. Beat at medium speed until the batter is thick like honey, about 2 min. Fold in the pears and berries and scrape into the prepared pan, smoothing the top. Bake approximately 1 hour and 10 min., or until toothpick inserted in the center comes out clean (do not open the oven door to check until at least an hour has passed). Remove from oven and let cool on a rack for about 20 min., then remove cake from the pan and let cool completely. Trim the top crust to allow the cake to sit evenly if needed.