Pre-heat oven 350F (180C). Lightly grease and flour an 8 inch (20cm) cake pan.
In a medium bowl whisk together the flour, salt, baking powder and baking soda.
In a large bowl beat the butter, sugar and zest until creamy about 3 minutes, then add the egg and beat well, add the flour and combine, then add the yogurt and milk and beat until smooth approximately 1 minute. Spread evenly in the prepared pan and bake for approximately 30-35 minutes or until toothpick comes out dry or with a couple of crumbs attached. Let the cake cool to warmish then pour the frosting on the cake. Serve. Enjoy!
LEMON FROSTING
In a small bowl beat together the powdered sugar, butter and lemon juice until smooth.
Notes
You could also make a firmer icing and frost the cake when it is completely cool.
How to make homemade cake flour
You can make your own, for every cup of all purpose flour remove 2 tablespoons and substitute with 2 tablespoons of cornstarch. Be sure to sift them together to combine them well.
How to store it
Any leftover frosted cake should be chilled uncovered in the fridge for about 15 minutes so that the frosting firms up, and then the cake should be covered with plastic wrap. Before serving, the cake should come to room temperature, let it sit on the counter for about 30-45 minutes depending on how warm your house is.
How to freeze it
To freeze an unfrosted cake, be sure to let it cool completely, then wrap it in plastic wrap and then again in foil, place it in a freezer safe bag or container. To thaw the cake, remove the bag and foil and let it thaw in the plastic wrap at room temperature. It will keep for up to 3-4 months in the freezer.To freeze a frosted cake, place the cake on a cookie sheet and freeze until frozen, very firm. Then wrap it in plastic wrap and foil. Place it in a freezer safe bag or container. To thaw, leave the cake at room temperature wrapped in plastic wrap. It will keep for up to two months in the freezer.