Lemon Poppy Seed Cupcakes

These crazy moist Lemon Poppy Seed Cupcakes are the prettiest, easiest, most delicious cupcakes you will ever make! Poppy seeds and lemon are match-made in heaven, the perfect cupcake flavor combination you must try!

Best lemon poppy seed cupcake recipe

These poppy seed and lemon cupcakes are fluffy, tender with incredible aromatic lemon flavor, packed with poppy seeds, filled with tangy lemon curd, and covered with an easy whipped mascarpone frosting. They're one of my favorite lemon desserts!

You won't need any fancy kit or ingredients, and the recipe comes together really easily. This recipe is perfect for beginner bakers, but everyone is always so impressed!

My lemon curd recipe that we use for the filling is incredibly creamy, tangy, and buttery. It's made with egg yolks for extra richness and fresh lemon juice for the best flavor. It's the perfect filling for your poppy seed muffins. And the whipped mascarpone frosting is perfectly balanced and just as delicous as buttercream!

Katalin's Key Take on how to make moist cupcakes

Baking is science, so using the right ingredients and techniques is essential to achieve the best results. And you all want super moist cupcakes, right?

These cupcakes will stay super moist and tender for days after baking. The secret tip (although I share it all the time) is to use a baking hack that gives them extra lift and lightness.

Before baking – mix a small amount of white vinegar with baking soda and fold it into the batter. I'll show you exactly how to use this hack below, but I promise it will make cupcakes airy and much lighter than any cupcakes you have baked before.

Start with the lemon curd filling

Zest both lemons using a microplane grater and set aside.

Juice the lemons into a heatproof bowl with the room-temperature egg yolk and sugar. Place this bowl over a saucepan of simmering water (not boiling), but do not let the bowl touch the water.

Cook the curd over medium-high heat in the double boiler while whisking constantly to avoid the egg scrambling. The curd will thicken to a custard consistency after 8-10 minutes, and if you have a thermometer, it will read 80C /176F.

Pour the cooked curd through a sieve to ensure no lumps, and then mix small chunks of softened butter one at a time with a rubber spatula. Make sure each butter chunk is fully incorporated before adding the next.

Fold in half of the grated lemon zest and pour the curd into a jar. Cover the surface with plastic wrap to prevent skin from forming and place it into the fridge, where it will continue to thicken as it cools.

Make the lemon poppy seed cupcake base

Preheat your oven to 175℃ / 350℉ (no fan) and line a cupcake tin with muffin liners.

Massage the remaining lemon zest into the white granulated sugar with your fingertips. This heightens the lemon flavor.

Use an electric hand whisk to cream the room-temperature butter and the lemon sugar together until light and fluffy. This will take a few minutes.

Add the room-temperature eggs one by one while the mixer is still running, and then add the vanilla extract.

Sift together the flour, baking powder, and salt (the dry ingredients). Never skip the salt; it balances sweetness and enhances the flavors!

Add the dry ingredients to the wet mixture in thirds, alternating with the room-temperature milk. Have the mixer on the low-speed setting for this stage, and stop as soon as the ingredients are incorporated to avoid overmixing. Finally, fold in the poppy seeds.

Mix vinegar with the baking soda, which will foam and bubble. Immediately fold this mixture into the lemon poppyseed cupcake batter.

Pipe or spoon the batter evenly into the prepared cupcake tin, filling each about ¾ full. Do not overfill, or they will mushroom!

Bake the cupcakes for 20-22 minutes in the preheated oven. They are ready when an inserted toothpick comes out clean with no sticky batter. Do not overbake.

Allow the baked cupcakes to cool completely on a wire rack. Do not fill or frost while warm, as the filling and frosting can melt and go runny.

Whip up the mascarpone frosting

Whip the mascarpone, cold heavy cream, and sifted powdered sugar with an electric hand mixer for a minute or two just until it reaches a creamy, fluffy consistency.

Make a small hole in each poppy seed cupcake with a spoon and fill them with lemon curd.

Pipe frosting onto each cupcake and decorate with more poppy seeds before serving. I also like to add edible flowers!

Storing and freezing

Store leftover lemon poppyseed cupcakes (if there are any) covered and refrigerated for 1-2 days. Bring them back to room temperature before serving so the frosting can soften slightly before you enjoy them.

You can freeze the lemon poppy seed cupcake base without filling or frosting. Wrap them in plastic food wrap to prevent freezer burn, and place them into a ziplock bag.

You can also freeze lemon curd, place it in an airtight container, and cover the surface with plastic food wrap.

I do not recommend freezing mascarpone frosting, as defrosting can affect the texture.

Flavor variations

Once you have mastered this easy lemon and poppyseed cupcake recipe, you can tweak it to suit you and have some fun.

Try making a different citrus curd filling, using oranges instead. I also love to use my mango curd in cupcakes!

Alternatively, this recipe can be made by adding different spices, such as a pinch of ground cardamom, to the batter.

You can also try some of my other cupcake frostings with this recipe. I recommend my Swiss Meringue Buttercream that you can also flavor with lemon zest!

Ingredient substitutions

Sadly, I am never able to provide exact substitutes for different types of allergies and diets. Baking is science, so leaving out ingredients entirely will cause problems! If you substitute ingredients, you must also adjust the quantities and ratios of the other ingredients in the recipe.

If you want to try a different flour or make the cupcakes gluten-free, read my flour guide for suggestions. You can also read about how to use egg substitutions (or try one of my other egg-free desserts).

Check out my baking guides section to learn more about common baking ingredients and how to make the best swaps.

What equipment to use

Always weigh ingredients by the gram using a digital scale for accuracy.

Combine ingredients using an electric hand mixer and then switch to a rubber spatula to avoid overmixing the batter.

Bake the cupcakes in a 12 cup muffin pan prepped with cupcake liners and let them come down to room temperature on a wire cooling rack.

Invest in an inexpensive Digital oven thermometer to ensure you are baking at the right temperature and avoid dry cupcakes.

Use a piping bag fitted with a French star nozzle tip to frost the cupcakes like a pro.

Expert tips to make lemon poppyseed cupcakes

1. I recommend making the lemon curd first; it needs time to set in the fridge. Meanwhile, bake the cupcakes. Prepare the whipped mascarpone frosting once the poppy seed muffins and lemon curd filling are cooled.
2. Make sure you are using room temperature ingredients where specified. Always use room temperature eggs in baking and ensure the milk is not cold either. The unsalted butter for the lemon curd and cupcakes must also be softened at room temperature. This can mean taking it out of the fridge an hour ahead. Read my post on how to soften butter.
3. Don't overmix cupcake batter, or it can overproduce gluten, making the cupcakes tough. Stop as soon as the ingredients are incorporated.
4. The mascarpone and heavy cream should be high in fat and very cold.
5. If you do not have mascarpone, feel free to replace it with full-fat cream cheese and make cream cheese frosting instead.
6. Never frost-warm cupcakes.
7. Applying a soaking syrup (like lemon syrup) to the cupcakes will also make them super moist and flavorful, although this is optional.
8. Make my macaron recipe with the leftover egg whites!

Try some of my other cupcakes recipes

• Chocolate caramel cupcakes
• Raspberry cupcakes
• Oreo cupcakes
• Mango cupcakes
• White chocolate raspberry cupcakes

If you love these easy lemon poppy seed cupcakes with lemon curd filling as much as I do, check out this round-up of the best filled cupcake recipes for inspiration on what to bake next!

Have you tried this recipe?

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