Note; To better synchronize the downtime in these recipes below, make the →lemon curd first, and then the lemon cupcakes.
 

Directions  for the Lemon Cupcakes
 

• The temperature of your butter is often the key to proper mixing. If your butter is too cold, it won’t whip up light enough; but if it’s too soft, it can’t hold enough air to leave a cupcake. You will know it’s right if it is soft but still holds its shape when you pick it up. If the butter droops or your finger melts right into it, it’s too soft.  If you can easily press your fingers into the butter, it's too cold. Cutting the butter into small pieces will help to warm faster too.
   
• Make sure your eggs, and yogurt is at room temp, You don’t want to add cold eggs or cold yogurt to perfectly whipped butter or the butter will seize and you’ll lose the fluffy air you created. if your eggs are not at room temperature when you are ready to mix your cupcake batter, warm them in the shell by placing the eggs in a bowl of hot tap water for 5 minutes before starting this recipe.
   
• Preheat the oven to 350 F (180 C). Line two 12-cup muffin pans with standard-size cupcake liners and set them aside. 
   
• In a large bowl, sift together 290 grams all-purpose flour and 3 teaspoon of baking powder; sifting the dry ingredients together not only eliminates lumps but also evenly distributes the leavening agent's trough out, giving you more fluffy cupcakes. Add 300 grams superfine sugar and whisk together. set aside for now.
   
• Add 200 gram unsalted butter into the bowl of a stand mixer fitted with the whisk attachment, or use the paddle attachment instead.  It's super-tempting to turn the mixer on high speed and let it whip the butter but resist the urge. If you mix on medium speed instead. You’ll get smaller air bubbles in the mixture; these will be stronger and create a far superior cupcake texture. It may take some extra minutes, but the cupcake will be worth it.
   
• Mix the butter on medium-high speed until pale and fluffy, this takes about 4 to 5 minutes. Make sure to stop the mixer at times and take time to scrape the sides and bottom of the mixing bowl and also shake out the butter that collects inside your whisk as well. For this lemon cupcake recipe, it is so important to take the time to properly cream the butter do not rush through this process. This process will give you a tender and velvety lemon cupcake.
   
• As soon as the butter is properly creamed, add finely grated lemon zest using a fine grater or a zester, rub the lemon in one direction again on the blades. turn the lemon as you go, so you only remove the yellow skin, the white part underneath is bitter.
   
•   Add the flour /sugar mixture, the eggs, lemon juice, vanilla bean paste, and yogurt to the creamed butter mixture. With the mixer on the lowest setting, beat slowly for only → 10 seconds. You want to mix as little as possible so you don’t get the gluten all excited.
   
• Stop the mixer scrape down the sides and bottom of the bowl again, and shake out the batter that collects inside your whisk as well. Attach the whisk attachment again.
   
• With the mixer on the lowest setting, ( with about 10 high-speed pulses in between) mix until well incorporated, and until all traces of egg have disappeared but not more than → 20 seconds altogether. You want to mix as little as possible so you don’t get the gluten all excited.
   
• Remove the bowl from the mixer, Use your spatula, and scrape the side and bottom of the bowl to incorporate any dry ingredients that may have settled there. Combine with your spatula 
   
• Using an ice cream scooper with a trigger release, scoop the batter into the cupcake liners, filling each three-fourths full. Be careful not to overfill.
   
• If time permits; let the batter rest for → 20 minutes, it makes for better cupcakes. ( optional) otherwise, proceed as directed.
   
• Bake for 20 to 23 minutes, or until a toothpick inserted into the center of a cupcake comes out mostly clean but still moist. 
   
• Let them cool in their pans for a few minutes, then quickly remove the cupcakes from their pans and allow them to completely cool on a wire rack before filling/frosting.
   
• Lightly cover the cupcakes with foil or plastic wrap so they do not dry out.
   
• Without frosting, these cupcakes can be reheated in the microwave for a few seconds and will give you a warm and delicious lemon cupcake just as they come straight from the oven. 

lemon curd
 

• If you are going to add lemon zest to the lemon curd, be sure to scrub the lemons with a little liquid dishwashing detergent, rinse well, and dry before zesting.
   
• I use a Microplane zester to collect all the wonderful lemon zest.
   
• Before juicing the lemons, give them a good roll on the work surface to release as much juice as possible.
   
• In a large bowl add 180 gram powdered sugar, 35-gram cornstarch, 4 large eggs, two egg yolks, zest from 2 lemons ( optional), 250 grams freshly squeezed lemon juice, whisk it all together into a homogenous mixture using a whisk or an immersion blender.
   
• Pour the content of the bowl into a medium-size saucepan and cook over medium-low heat, constantly stirring with a whisk or spatula and scraping the sides of the pan as needed, until thickened to a consistency resembling pudding. This step takes about 5 minutes.
• When the lemon curd has thickened slightly, like pudding, remove from heat, add in 150-gram cold heavy cream, and stir to combine.
   
• This step is optional. I love to blend the finished lemon curd with an immersion blender for a few seconds to emulsify the lemon curd. 
   
• Transfer the lemon curd right away to an airtight jar or a bowl. Press a piece of plastic wrap against the lemon curd to create an airtight seal and chill in the fridge.
   
• One recipe makes about 725 grams.
   
• The Lemon curd will keep refrigerated in an airtight container for two weeks. (Longer storage dulls the fresh citrus flavor.)
   
• If your lemon curd feels too thick, just give it a quick whisk ( about 5 seconds) to loosen it up.

Marshmallow frosting

• Pour about 4 cm ( 2- inches ) of water into a medium saucepan and place over medium heat.
   
• Wipe your mixer bowl, your whisk attachment and your hand whisks with a paper towel dampened with a little lemon juice to eliminate any trace of grease.
   
• Separate the egg whites from the yolks. For best results, use fresh egg whites (often, boxed whites don’t whip up). Cleanly separate the egg whites from the yolks. Any bit of yolk can prevent the whites from whipping up. I like to crack the egg on a flat surface, open it up into a small bowl and then fish out the yolk with a clean hand. This is best done when the eggs are cold, but whites whip up best when they are at room temperature.
   
• Place 120 grams of egg whites, 250 grams superfine sugar, two tablespoons glucose or light corn syrup, one tablespoon of water (→the water makes the whipped meringue light and airy), and a pinch of cream of tartar into a perfectly clean bowl of your stand mixer. Whisk the ingredient together to make a thick slurry.
   
• Place the bowl over the pan of simmering water ( make sure the pan is small enough that the bowl sits above the water and not directly touching it, or you may end up with scrambled egg whites.
   
•  Whisk constantly but gently until the mixture reaches 54C°/129F° ( about 7 minutes). Be sure your sugar-egg white mixture is hot enough to dissolve the sugar, or you will end up with grainy frosting.
   
• Once all the sugar has melted, transfer the bowl to the mixer fitted with a whisk attachment. 
   
• Whip on low speed for a minute, then whip on medium-high speed for 4 to 5 minutes or until the mixture has tripled in volume, is fluffy and glossy, and looks like shaving cream.
   
• Add seeds from 1/2 vanilla bean or 1 teaspoon vanilla bean paste at the very end of beating and whip on low speed until just combined. 
   
• Make sure not to over-whip the marshmallow frosting. It can get pretty thick and stiff if you overmix it and make it difficult to pipe onto your cupcakes.
   
• Use it immediately to frost your beautiful cupcakes.
   

How to assemble the Lemon Meringue cupcakes
 

• Once the Lemon cupcakes have cooled, use a small, sharp knife or an apple corer or a melon baller to scoop out the center of each cupcake cake, creating a well. Make sure your cupcakes are cooled or they could collapse if you try to core them when they are hot.
   
• Fill a pastry bag fitted with a small round tip with the lemon curd and pipe it into the cupcakes all the way to the top. ( You can also use a small spoon to fill the cupcakes instead).
   Cover the top of the lemon curd-filled lemon cupcake lightly with plastic wrap and set it aside while you make the Marshmallow Frosting.
   
• Make the marshmallow frosting; fit a pastry bag with a large round nozzle Wilton #1A and fill with the marshmallow frosting, Pipe generous swirls of the marshmallow frosting on top of each cupcake.
   
• Using a kitchen torch( on the lowest setting) carefully brown the marshmallow frosting, moving the flame back and forth to avoid burning.
   
• Serve immediately, or store in an airtight container at room temperature for no more than 4 hours. ( serving immediately is highly recommended)