Lemon Poppy Seed Cupcakes with Blackberry Frosting

There’s something undeniably special about the combination of bright citrus and juicy berries. These Lemon Poppy Seed Cupcakes deliver a soft, tender crumb infused with fresh lemon zest and poppy seeds, topped with a naturally flavored blackberry buttercream that’s vibrant, fruity, and beautifully balanced.

This recipe leans into real ingredients. Fresh lemon zest and juice bring brightness, while blackberries are reduced into a thick, jam-like puree that gives the frosting its bold color and flavor. While store-bought blackberry preserves can be used to save time, the depth of flavor from real berries truly makes a difference.

Perfect for spring gatherings, summer celebrations, birthdays, or afternoon baking sessions, these cupcakes are elegant yet approachable. Let’s break down everything step-by-step so you get bakery-level results at home.

Why You’ll Love This Recipe

• Soft and fluffy lemon cupcakes with a tender crumb
• Fresh lemon zest and juice for authentic citrus flavor
• Naturally colored blackberry frosting from real berries
• Balanced sweetness with a slight tang
• Great make-ahead structure when prepared correctly
• Detailed method ensures consistent results

Ingredients Breakdown

Servings

14 cupcakes

Full Ingredient List (Exact Measurements)

Lemon Poppy Seed Cupcakes

• 1 1/2 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 1/2 cup unsalted butter, softened to room temperature
• 1 cup white sugar
• 2 tablespoons lemon zest
• 2 large eggs
• 1 teaspoon vanilla extract, room temperature
• 2/3 cup sour cream, room temperature
• 3 tablespoons lemon juice, freshly squeezed
• 1 1/2 tablespoons poppy seeds

Blackberry Frosting

• 1 1/2 cups blackberries, fresh or frozen
• 1 cup unsalted butter, softened to room temperature
• 4 cups powdered sugar
• 1/4 teaspoon salt
• 1 tablespoon cream (if needed)

Tools & Equipment Needed

• 2 muffin pans
• Cupcake liners
• Large mixing bowls
• Hand mixer or stand mixer
• Fine mesh sieve
• Blender or food processor
• Small-medium saucepan
• Rubber spatula
• Wire cooling rack
• Piping bag (optional, 1M tip if piping)
• Measuring cups and spoons

Step-by-Step Instructions

Lemon Poppy Seed Cupcakes

1. Preheat and Prepare

Preheat the oven to 350°F (175°C).

Line 2 muffin pans with cupcake liners. This recipe yields about 14 cupcakes.

2. Combine Dry Ingredients

In a large bowl, sift together:

• 1 1/2 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt

Whisk together and set aside.

3. Cream Butter, Sugar & Lemon Zest

In a separate large bowl, beat:

• 1/2 cup unsalted butter
• 1 cup white sugar
• 2 tablespoons lemon zest

Beat until fluffy and well combined. The lemon zest releases essential oils into the sugar, intensifying the citrus flavor.

4. Add Eggs and Vanilla

Beat in:

• 2 large eggs
• 1 teaspoon vanilla extract

Mix until fully incorporated.

5. Alternate Sour Cream and Flour

With the mixer on low speed:

Beat in about 1/2 of the 2/3 cup sour cream.

Then add about 1/2 of the flour mixture.

Turn off the mixer and scrape down the sides of the bowl.

Repeat with the remaining sour cream and flour mixture.

Mix only until combined. Do not overmix.

6. Fold in Lemon Juice and Poppy Seeds

Gently fold in:

• 3 tablespoons freshly squeezed lemon juice
• 1 1/2 tablespoons poppy seeds

The batter should be smooth and slightly thick.

7. Fill and Bake

Spoon the batter into prepared liners, filling each about 2/3 full.

Bake one tray at a time on the middle rack for 16–20 minutes, until tops look set and a toothpick inserted comes out clean.

Cool in the pan for at least 10 minutes, then transfer to a wire rack to cool completely.

Blackberry Frosting

1. Blend Blackberries

Add:

• 1 1/2 cups blackberries

Blend until smooth.

2. Remove Seeds

Press the puree through a sieve to remove seeds. Work in batches and use the back of a spoon to push it through.

3. Reduce the Puree

Transfer the seedless puree to a small-medium saucepan over low heat.

Bring to a gentle simmer, stirring occasionally for 10–20 minutes, until thick like jam.

Remove from heat and cool completely.

You should have about 2–4 tablespoons of thick puree.

4. Beat the Butter

In a large bowl, beat:

• 1 cup unsalted butter

Beat until soft and smooth.

5. Add Sugar and Salt

Turn mixer to low and beat in:

• 2 cups powdered sugar
• 1/4 teaspoon salt

6. Add Blackberry Puree

Beat in:

• 2 tablespoons thick, cooled puree

7. Finish Frosting

Add the remaining powdered sugar about 1/2 cup at a time.

Add more blackberry puree or 1 tablespoon cream if needed for consistency.

Beat until smooth and fluffy.

8. Frost the Cupcakes

Transfer frosting to a piping bag or frost with a knife.

Ensure cupcakes are fully cooled before frosting.

Flavor Profile & Texture

These cupcakes are:

• Bright and citrusy
• Light with a moist crumb
• Slightly tangy from sour cream
• Fruity and naturally vibrant from blackberry reduction

The poppy seeds add subtle texture without overpowering the cake.

Nutritional Overview (Per Cupcake with Frosting)

• Calories: 462 kcal
• Carbohydrates: 61 g
• Protein: 3 g
• Fat: 24 g
• Saturated Fat: 14 g
• Cholesterol: 90 mg
• Sodium: 147 mg
• Potassium: 109 mg
• Fiber: 1 g
• Sugar: 49 g
• Vitamin A: 769 IU
• Vitamin C: 6 mg
• Calcium: 56 mg
• Iron: 1 mg

Dietary Notes:

• Vegetarian
• Contains gluten and dairy

Make-Ahead & Storage Tips

• Best made the day you plan to serve.
• Store frosted cupcakes in an airtight container at room temperature for up to 6 hours.
• Refrigerate up to 3 days. Bring to room temperature before serving.

For making ahead:

• Bake cupcakes and store airtight at room temperature.
• Make blackberry puree and refrigerate separately.
• Prepare frosting the day of serving.

FAQs

Can I use bottled lemon juice?

No. Freshly squeezed lemon juice is essential for proper flavor balance.

Can I use blackberry preserves instead?

Yes. Use 3 tablespoons total if substituting.

Why not double the recipe?

Doubling can cause overmixing and lead to dense cupcakes.

Can I freeze them?

Freeze unfrosted cupcakes up to 2 months.

Cooking Timeline

Stage	Time
Prep	45 minutes
Bake	16–20 minutes
Cooling	45 minutes
Total	2 hours

Serving Suggestions

• Garnish with fresh blackberries or lemon zest.
• Pipe tall swirls for bakery-style presentation.
• Serve slightly cool but not cold for best texture.

Pro Baking Tips

• Zest lemons before juicing.
• Use room temperature ingredients for smooth batter.
• Do not overmix once flour is added.
• Fully cool blackberry reduction before adding to frosting.

Storage & Freezing Guide

Room Temperature:
Up to 6 hours in airtight container.

Refrigerator:
Up to 3 days.

Freezer:
Unfrosted cupcakes freeze up to 2 months.

Conclusion

These Lemon Poppy Seed Cupcakes with Blackberry Frosting combine bright citrus, tender crumb, and real berry flavor into one elegant dessert. The fresh lemon zest and reduced blackberry puree elevate them beyond standard cupcakes.

If you want something vibrant, balanced, and full of fresh flavor, this recipe delivers every time. Bake them once, and they’ll quickly become a favorite in your rotation.

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