Preheat oven to 350 degrees F. Spray 9-inch loaf pan with cooking spray.

Cream together butter, ricotta with sugar until light and fluffy about 3 minutes. Add eggs one at a time following by the lemon zest, lemon juice, and vanilla extract.

In a separate bowl, mix together the flour with the baking powder, baking soda, and salt. Add the dry ingredients to the ricotta mixture, stirring just until combined. Pour batter in the loaf pan. Bake for 45 minutes - 1 hour or until a toothpick inserted in the center comes out clean. Let cool on a wire rack.

Mix together the powdered sugar with lemon juice until well combined. Spread the frosting on the cooled cake. Serve.