When the cake cools down, it can be covered with glaze. To do this, take 50 g of powdered sugar and pour into a deep plate. And gradually, add lemon juice with a teaspoon. Add, mix, add more. As soon as the whole powder gets wet, and the mass is even thicker – the glaze is ready. Pour (or smear) cupcake with it, it will harden quickly. And here are the options. If you dilute only with lemon juice – it will be decently sour, as for me – it is perfect. If in doubt, use juice + water in proportion 1:1, or just water. Sprinkle another damp glaze on top with the zest of the third lemon.