In a large mixing bowl combine the butter and sugar with lemon zest. Using a hand mixer, whisk the mixture until light and fluffy. Scrub the sides of the bowl using a spatula.
Next, add one egg at a time, mixing well between each addition. For your convenience, you can use a stand mixer instead of a hand mixer for this step. Add the lemon juice and mix for 10 more seconds. Scrub the sides of the bowl one more time.
In a separate mixing bowl, sift the flour, baking powder and salt. Give it a quick mix.
Add half of the dry ingredients to the egg mixture. Give it a stir with a spatula to mix the flour into the cake batter, then using a hand mixer, combine all together at the lowest speed of your mixer. Add the second half of the dry ingredients and repeat the process. Scrub the sides of the bowl one more time.
Next, let’s prepare the baking dish. I have a 9 by 9-inch glass dish and today I'm going to use a classic butter and flour combo. Carefully coat the baking dish with the melted butter using a brush. Next, sprinkle flour across the whole dish, lifting and turning it as needed to ensure it is coated. Make sure to get rid of any excess flour before pouring in your cake batter, otherwise, you could end up with a dry pocket of flour in the final product.
Transfer the cake batter into the baking dish, spread it evenly and bake at 350 F degrees for 50-55 minutes or until the skewer inserted into the cake comes out dry. Let the cake cool completely before frosting.
In a mixing bowl combine the cream cheese and softened butter. Using a hand mixer, whisk for about a minute. Add half of the powdered sugar. Give it a stir with a spatula to mix the powdered sugar into the batter mixture, then using a hand mixer, combine all together at the lowest speed of your mixer. Add the second half of the powdered sugar, lemon juice and lemon zest. Again, give it a quick mix with a spatula, then combine all together at the lowest speed of your mixer. The lemon cream cheese frosting should turn out white and fluffy. When the cake has cooled down, you can frost the cake directly in the baking dish or you can cover the cake with the cutting board and turn it upside down. Remove the baking dish,cover the cake with a cooling rack or a serving plate again and turn it upside down one more time.
Using a spatula, gently spread the frosting on top of the cooled cake. You can divide the lemon cake into 9 large pieces or into 16 smaller pieces and decorate them with a piece of lemon, or sprinkle some lemon zest.