1. Preheat the oven to 350 degrees F. Grease a 9 by 5 by 3-inch loaf pan with butter. In a medium bowl combine the flour, baking powder, and salt. Whisk to combine.

2. Using an electric mixer, cream together the butter, ricotta cheese,  and sugar until light and fluffy, about 3 minutes. With the machine running, add the eggs one at a time. Add the vanilla and lemon zest and mix until combined.

3. Add the dry ingredients, a small amount at a time, until just incorporated. Pour the mixture into the prepared loaf pan and bake until a toothpick comes out clean and the cake is beginning to pull away from the sides of the pan, about 45 to 50 minutes. Let the cake cool in the pan for 10 minutes then transfer to a wire rack to cool completely.

4. Meanwhile, place the mixed berries in a small bowl with the remaining 1 tablespoon sugar. Stir well and set aside until serving time.

5. To serve, slice the pound cake and serve with a spoonful of mixed berries. Top with whipped cream, if desired.