We beat the butter and sugar in a deep and wide bowl until obtaining a creamy and whitish mixture. Add the eggs, one at a time , and mix well before adding the next. Add the vanilla essence, the lemon juice (reserving two tablespoons for the final glaze) and stir to integrate.
In a separate container, mix the flour, baking powder, salt and lemon zest well. Add the mixture to the previous container, little by little and stirring well so that there are no lumps . Peel and grate the apples and stir gently until obtaining a homogeneous mass. We fill a 28 cm cake mold with it, with the base and walls greased and covered with greaseproof paper.
We introduce the mold in the lower half of the oven , preheated to 180 ºC with heat up and down, and cook for approximately 45-50 minutes. Let cool before covering with the lemon glaze, which we prepare by mixing the icing sugar with the two reserved tablespoons of lemon juice.