Heat the oven to 325° F. Spray an 8 x 5 x 3-inch loaf pan with a nonstick coating.
Whisk together the flour, baking powder and salt until well blended.
With an electric mixer, beat the cream cheese and butter until very pale and little tails have formed. Sprinkle in the sugar and beat well until slightly fluffy. Scrape the sides of the bowl well. Add the eggs, one at time, beating until blended before adding the next egg. With the mixer on low, add the flour, vanilla extract and lemon zest, and mix until almost incorporated. Switch from the mixer to a stiff rubber spatula and mix until the batter is well blended and smooth, taking care to scrape the bowl's bottom and sides. Gently fold in the berries. Scrape the batter into the loaf pan and bake in middle of the oven until the cake is golden brown and a wooden pick comes out with just a few crumbs clinging to it when inserted in the center (60 to 65 minutes if using fresh berries; 75 to 90 minutes if using frozen berries).
Let the cake cool for 15 minutes and then invert the pan and lightly tap the bottom to release the cake. Cool completely on rack before serving.Makes 4 Source: