Lemon Poppy Seed Cupcakes with Blackberry Frosting

Nothing says spring quite like lemon desserts. The bright, zesty flavor of lemon paired with the subtle crunch of poppy seeds and the juicy burst of blackberry frosting creates a harmony of texture, color, and taste that’s perfect for every occasion—baby showers, brunches, or just a beautiful weekend bake.

These lemon poppy seed cupcakes are moist, fluffy, and have just the right balance of tart and sweet. The blackberry frosting not only looks stunning but tastes like a spoonful of spring. Plus, they’re easy to make, even for beginner bakers!

Why Lemon and Poppy Seeds Work So Well Together

Lemon brings a tangy brightness, while poppy seeds add a mild nuttiness and subtle crunch that make every bite interesting. In addition to taste, they have some nutritional perks.

According to Healthline, fresh lemon juice is rich in vitamin C and antioxidants, supporting immunity and digestion. And The Spruce Eats explains how poppy seeds enhance both the flavor and texture of baked goods, while offering small amounts of calcium and iron.

The Perfect Blackberry Frosting

The combination of tart blackberries with sweet buttercream frosting is simply irresistible. And it’s not just delicious—it’s healthy too! Blackberries are full of fiber and antioxidants, as seen in the USDA’s nutritional profile. You can use fresh or frozen berries, but fresh will give the most vibrant color and flavor.

The color contrast of deep purple frosting on a light yellow cupcake also makes for a visually appealing treat that’s perfect for special occasions or gifting.

Ingredients Breakdown

🧁 For the Cupcakes

• 1 ½ cups all-purpose flour

• 1 tsp baking powder

• ½ tsp baking soda

• ¼ tsp salt

• ½ cup unsalted butter, room temp

• 1 cup white sugar

• 2 tbsp lemon zest

• 2 large eggs

• 1 tsp vanilla extract

• ⅔ cup sour cream, room temp

• 3 tbsp fresh lemon juice

• 1 ½ tbsp poppy seeds

🍇 For the Blackberry Frosting

• 1 ½ cups fresh or frozen blackberries

• 1 cup unsalted butter, room temp

• 4 cups powdered sugar

• ¼ tsp salt

• 1 tbsp heavy cream (optional)

Step-by-Step: How to Make Lemon Poppy Seed Cupcakes

1. Preheat and Prep

• Preheat oven to 350°F (175°C)

• Line muffin pans with cupcake liners (makes ~14 cupcakes)

2. Combine Dry Ingredients

• Whisk together:

  • Flour

  • Baking powder

  • Baking soda

  • Salt

3. Cream Butter and Sugar

• Beat butter, sugar, and lemon zest until light and fluffy

4. Add Wet Ingredients

• Add eggs one at a time

• Mix in vanilla extract

5. Alternate Adding Sour Cream and Flour Mixture

• Add half the sour cream, then half the dry ingredients

• Repeat, mixing gently

6. Fold in Lemon Juice and Poppy Seeds

• Gently stir in lemon juice and poppy seeds

7. Fill and Bake

• Fill liners ⅔ full

• Bake for 16–20 minutes until golden and springy

• Cool completely on a wire rack

Making the Blackberry Frosting

Step 1: Make the Blackberry Puree

• Blend the blackberries until smooth

• Press through a sieve to remove seeds

• Simmer puree on low heat for 10–20 minutes until thick like jam

• Cool completely

Step 2: Make the Buttercream

• Beat butter until smooth

• Add 2 cups of powdered sugar and salt

• Add 2 tbsp of the cooled blackberry puree

• Beat until fluffy, adding more puree or cream for consistency

• Add remaining sugar gradually

Step 3: Frost the Cupcakes

• Transfer to a piping bag or frost with a knife

• Garnish with fresh blackberries or lemon zest

Pro Baking Tips

• Use fresh lemon juice for the best flavor—bottled juice can be bitter.

• Don’t overmix the batter to keep cupcakes tender.

• Make the blackberry puree first so it cools while the cupcakes bake.

• Room temperature ingredients mix better and rise more evenly.

Decoration Ideas

• Use a large star piping tip (e.g., 1M) for a bakery-style swirl

• Top with a single fresh blackberry and lemon zest strips

• Dust lightly with powdered sugar for an elegant touch

Storage and Make-Ahead Tips

• Best served the day they’re made

• Store at room temp (in airtight container) for up to 6 hours

• Refrigerate for up to 3 days

• Freeze unfrosted cupcakes for up to 2 months

Nutrition Information (Per Cupcake with Frosting)

• Calories: ~462

• Carbohydrates: 61g

• Fat: 24g

• Sugar: 49g

• Protein: 3g

• Fiber: 1g

• Vitamin C: 6mg

Note: Nutrition varies based on portion and ingredient brands.

FAQs: People Also Ask

❓ Can I use store-bought blackberry preserves instead?

Yes! You can replace the homemade puree with 3 tablespoons of good-quality preserves. However, fresh puree offers the best color and flavor.

❓ How long do lemon poppy seed cupcakes last?

They stay fresh for 2–3 days in the fridge. For best texture, bring to room temp before serving.

❓ What can I substitute for sour cream?

You can use plain Greek yogurt or buttermilk as a substitute in equal measure.

❓ How do I make the frosting seedless?

Strain the puree through a fine mesh sieve before adding to the buttercream to eliminate seeds.

❓ Can I use other berries for the frosting?

Absolutely. Raspberries and strawberries work well, just follow the same reduction process.

Final Thoughts

These lemon poppy seed cupcakes with blackberry frosting are a delightful way to celebrate the flavors of spring and summer. With their bright citrusy base, crunchy poppy seeds, and luscious berry topping, they’re as fun to eat as they are to make.

So whether you’re baking for a special occasion or simply treating yourself, this recipe delivers flavor, texture, and beauty in every bite.