Soft lemon whoopie pies filled with bright blueberry buttercream are easy to make with the help of a cake mix. They are a perfect handheld treat for spring and summer.

There is just something about the combination of bright citrusy lemon and berries. Putting them together in the form of whoopie pies means you get the best part of cookies and cake in a fun little package.
They are sweet, tart and perfectly portable. So they are wonderful for parties, picnics, bbqs and more.
Not only is the flavor bright and cheery, the colors are too. These fun whoopie pies are sure to pyr a smile on your face.
Making the Whoopie Pies
The soft cakey cookies that make the outside of the sandwich only take a few ingredients. Starting with a lemon cake mix makes them super simple.
A stick of softened butter, eggs and a little bit of sour cream is all you need. In fact the sour cream is the only ingredient you have to measure, the rest is just counting.

The key to getting fluffy rounded pillowy whoopie pies is to chill the scoops of batter before you bake them. That will help the cookies stay proud and round rather than spreading and flattening.
Use a cookie scoop to get the sticky batter most of the way shaped. After a half hour in the refrigerator, gently press down any ridges or pointy bits of batter.
The next key is to bake them enough that they are finished but not too mich. You want the final texture to be soft and cakey.

So try not to let them get too much color. If you hit it just right, they are a thing of glory.
After a couple of minutes to set up on the pan, go ahead and remove them to a wire rack.
Once they are cooled completely, they are ready to be filled. Now the fun can really begin!
Filling Your Whoopie Pies
These fun whoopie pies are filled with blueberry buttercream. It’s a traditional American style buttercream that is flavored with freeze dried blueberries and a splash of lemon juice.
Of course they would also be delicious with marshmallow fluff buttercream or marshmallow buttercream made with actual marshmallows if you want to stick to the more traditional marshmallow filling.

Or use lemon sweetened condensed milk buttercream if you want to go full lemon. Or use strawberry buttercream for a strawberry lemonade inspired treat.
You could just scoop on a bit of frosting or smear some on with a knife. I like to use a piping bag and a star shaped tip because it is just as fast for me and a little more fun.

Little Dude actually piped the centers on these while I took pictures for the video. He is really turning into a fabulous helper!
How do I store these whoopie pies?
These lemon blueberry whoopie pies are best within a few days of the time they are made. However, can be stored in an airtight container at room temperature for up to a week.
More Fun Handheld Treats
If you want a deeper flavored whoopie pie, try out chocolate whoopie pies with peanut butter marshmallow filling. They feature that popular mix of flavors in a fun soft dessert.
Oatmeal cream pie bars are another fun twist on a classic. They have a molasses-y oatmeal cookie bar base with marshmallow fluff frosting that come together to taste a lot like packaged oatmeal creme pies.

Or whip up some soft sugar cookie bars. We like ours with a healthy dose of buttercream on top and they remind us of Lofthouse cookies.
Maw-maw’s toffee bars are a brown sugar and butter based cookie bar topped with a layer of chocolate.
Whew! Now I want one of each. I love how easy all of these are to serve and eat at a gathering.
Love tasty recipes? I do too! Follow me on Pinterest for more delicious ideas!

Lemon Blueberry Whoopie Pies with a Cake Mix
Equipment
Ingredients
Whoopie Pies
- ½ cup butter softened
- 15.25 oz lemon cake mix
- 3 large eggs
- ¼ cup sour cream
Blueberry Filling
- ¾ cup butter softened
- 4 cups powdered sugar
- ¼ teaspoon salt
- 1 teaspoon vanilla ectract
- 2 Tablespoons lemon juice
- 1 cup freeze dried blueberries
Instructions
- Preheat oven to 350°F and line 3 baking sheets with silicone mats or parchment paper.
- In medium mixing bowl, beat butter until smooth and creamy.
- Add cake mix, eggs and sour cream, stir until combined.
- Scoop a Tablespoon (or small cookie scoop) full of batter onto the lined baking sheets, leaving plenty of room between mounds of batter.
- Refrigerate for at least 30 minutes.
- Bake for 9-10 minutes or until completely set.
- Cool on the baking sheet for 2 minutes then remove to a wire rack to cool completely.
- To make the frosting, beat the softened butter until smooth. Slowly mix in powdered sugar, salt, vanilla and lemon juice until combined.
- Turn blueberries into powder using either a food processor or blender. Add blueberry powder to frosting mixture.
- Adjust consistency with a little more milk or lemon juice if needed.
- Pipe or spread over 1/2 of the whoopie pies, then top with remaining whoopie pies.
Video
Nutrition
