This is one of those lemon cakes that just tastes better the day after. As the cake sits on the counter overnight wrapped in plastic wrap – the lemon flavor develops more, and you will get a more moist lemon cake.
 

Marzipan
 

• In a food processor, blend 100-gram almond flour/finely ground almonds, 45 grams white sugar, 45 grams powdered sugar, one teaspoon vanilla bean paste, and 15 grams to 20 grams egg white until you have smooth marzipan. 
   
• Wrap the marzipan in plastic wrap and chill in the fridge. If not used immediately.
   
• This recipe makes about 200 grams; You will need 125 grams.
   
• If you have chilled the marzipan in the fridge, you need to grate the marzipan before using it. If you are using the marzipan immediately to make the lemon cake cut the marzipan into small pieces.

Lemon Sugar

• Finely grate one lemon over 50 grams of superfine sugar or white sugar, and use your fingers to rub the ingredients together until the sugar is moist and fragrant.
• This lemon sugar will be used to drizzle on the inside of the springform.

Danish Lemon Cake

• Position a rack in the center of the oven; 30 minutes before baking, preheat the oven to 175C°/350F° or fan setting 165C°/325F°. If the oven isn't up to temperature when the cake goes in, the cooking time will change, and your cake might not be as glorious.
   
• Butter the inside of one springform 23 cm / 9-inches with softened butter, Place a parchment circle on the bottom of the pan to prevent the bottom of the cake from sticking. Add a few tablespoons of lemon sugar ( or use regular white sugar instead) and tap it around the inside of the pan until all the buttered surface is covered, then turn the pan upside down to tap out excess lemon sugar. 
   
• To get the lemon cake, you truly deserve, sift the flour mixture twice to get the flour as aerated and light as possible. First, in a medium bowl, sift together 120-gram all-purpose flour or pastry flour or cake flour, 75-gram potato starch, and three teaspoons of baking powder. 
   
• Using a stand mixer fitted with the paddle attachment, cream together 200-gram superfine sugar, 200-gram unsalted butter, 125-gram grated or soft pieces of marzipan, seeds scraped out from 1 vanilla bean, and 1/4 teaspoon (1 gram) citric acid on medium-low speed (never on high) until you have a smooth, creamy mixture. This step will take 3 to 5 minutes. Stop the mixer a few times, scraping down the bowl and paddle attachment to release any clinging butter or sugar.
   
• One by one, add the five eggs, beating for a minute after each goes in. The mixture might curdle, but this is a temporary condition. Stop to scrape down the bowl and paddle as needed.
   
• Add about one-third of the flour mixture to the butter-sugar -egg mixture and finely grated zest from 2 lemons, and mix on low speed until incorporated. About 10 seconds. Do not overmix, or your cake will not be light and fluffy. Stop the mixer and scrape the side and bottom of the bowl, and paddle well.
   
• Add half of the remaining flour mixture and 50 grams of freshly pressed lemon juice and mix on low speed until incorporated, about 10 seconds. Stop the mixer and scrape the side and bottom of the bowl, and paddle well.
   
• Add the remaining flour mixture and 100-gram sour cream and mix on low speed until incorporated about 10 seconds. Do not overmix! Stop the mixer and scrape the side and bottom of the bowl, and paddle well. Remove the bowl from the mixer stand. Scrape the side and the bottom of the bowl one more time.
   
• Scrape the batter into the prepared springform, and smooth the top.
   
• Bake in the center of the oven for about 40 to 45 minutes, or until a toothpick in the center of the cake comes out clean. If you feel that the top of the cake is browning too quickly. Gently cover the top of the cake with aluminum foil. The key to this lemon cake being moist is too not to overbake the cake.
   
• The top will be flat and most likely cracked down in the middle, transfer the springform to a rack.
   
• Five to 10 minutes before the cake is ready, make the lemon glaze; In a small saucepan over low heat, stir the 80-gram fresh lemon juice and 50 gram powdered sugar together until the sugar is completely dissolved. This takes about two minutes. The longer the lemon syrup simmers, the more it will reduce and thicken) For a lemon syrup that really soaks into this lovely lemon cake, keeps the lemon syrup reasonably runny. For a thicker. Glossier finish that sits more on top of the lemon cake (if you want to skip the lemon icing). Cook the lemon syrup for 10 minutes on low heat. Stir the lemon-sugar mixture often to make sure it does not burn.
   
• Once the cake is out of the oven, keep the cake in the springform and poke holes into the warm cake with a skewer or a fork. Then, slowly spoon or brush the syrup evenly over the lemon cake, giving it time to soak in gradually.
   
• Let the cake cool before you drizzle the lemon icing on top if you want additional tartness in this lemon cake.
   
• In a medium bowl, whisk together 150 grams of powdered sugar or confectioners sugar and  2 to 6 tablespoons of lemon juice. The lemon icing should be slightly thick.
   
• Pour the lemon icing over the cake's top and let it drip down the sides. Let the lemon icing harden for about 20 minutes.
   
• If you've got the time, wrap the completely cooled lemon cake in plastic wrap and let it sit on the counter overnight – The lemon flavor really develops with a leisurely rest.
   
• The glazed Lemon cake will keep for up to 3 days at room temperature. Use a glass cake dome, a sealed plastic container, or plastic wrap. You place the cake covered in plastic wrap in the fridge, but refrigeration might firm up the fat in the lemon cake, making it texture dense when enjoyed straight from the refrigerator. However, it will get back to being fluffy again. All you need to do is allow the cake to stand at room temperature for at least 1 to 2 hours before serving.