Preheat the Oven: Set your oven to 350°F (175°C). Prepare a 12-cup muffin tin by lining it with festive cupcake liners.
Combine Dry Ingredients: In a medium-sized bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. This step helps ensure that your dry ingredients are evenly distributed—set this mixture aside.
Cream Butter and Sugar: In a large mixing bowl, use an electric mixer to cream the softened butter and granulated sugar. Beat on medium speed for about 3-4 minutes until the mixture is light and fluffy, which helps add air for a fluffy cupcake texture.
Incorporate Eggs and Flavor: Add the eggs to the creamed mixture one at a time, mixing thoroughly after each addition. Next, stir in the fresh lemon zest and lemon juice. This adds a vibrant citrus flavor to your batter.
Mix in Dry Ingredients and Buttermilk: Gradually add the reserved dry flour mixture to the butter mixture, alternating with the buttermilk. Start with a third of the dry ingredients, followed by half the buttermilk, then repeat, ensuring to end with the dry mixture. Mix until just combined to avoid overmixing.
Add Raspberries: Gently fold the fresh raspberries into the batter with a spatula, taking care to keep them intact for bursts of flavor in each cupcake.
Fill Cupcake Liners: Using a spoon or a cookie scoop, fill each cupcake liner about two-thirds full with batter to allow room for rising.
Bake the Cupcakes: Place the muffin tin in the preheated oven and bake for 18-20 minutes. To check for doneness, insert a toothpick into the center of a cupcake; it should come out clean. After baking, let the cupcakes cool in the pan for about 5 minutes before transferring them to a wire rack to cool completely.
Prepare the Frosting: In a medium bowl, beat the softened butter until smooth. Gradually add the powdered sugar, lemon juice, and lime zest, mixing until creamy and well-blended. Adjust the consistency with a little more lemon juice if necessary.
Create a Raspberry Swirl (optional): If you choose to use raspberry puree, take a small amount of frosting and mix in the puree gently just to create a marbled effect.
Decorate: Once your cupcakes are cool, use a piping bag fitted with a star tip to pipe the frosting generously on top of each cupcake for a decorative touch.
Add Final Touches: Garnish each cupcake with a few fresh raspberries and a light sprinkle of lemon zest for an enhanced visual appeal and an extra zing of flavor.
Notes
For an extra touch, add a raspberry swirl to the frosting.