Blueberry Lemon Cupcakes

Preheat the oven to 350℉ (177℃). Line a cupcake pan with 12 cupcake liners.
In a small mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set aside.
In a separate bowl, combine the granulated sugar and lemon zest. Using your fingers, gently rub the zest into the sugar to release the lemon oils to infuse the sugar with lemon flavor.
In the bowl of a stand mixer fitted with a paddle attachment or in a large mixing bowl with an electric hand mixer, cream the lemon-infused granulated sugar, unsalted butter, and vegetable oil for a few minutes until light and creamy. Add the egg and sour cream and mix well until smooth.
Add in half of the flour mixture and mix until mostly combined. Then, pour in the whole milk and lemon juice and mix. Add the remaining dry ingredients and mix until the cupcake batter is combined and smooth. Scrape the sides and bottom of the bowl to ensure the ingredients are fully combined.
Portion the cupcake batter into the cupcake liners using a large cookie scoop about ⅔ full. Bake the cupcakes for 20 minutes or until the cupcakes bounces back when gently touched. Cool the cupcakes in the pan for 2 minutes and then transfer to a wire rack to cool completely.

In the bowl of a stand mixer fitted with a paddle attachment or in a large mixing bowl with an electric hand mixer, whip the room temperature unsalted butter for 5 minutes until light, pale, and creamy.
Add half of the powdered sugar and mix on the lowest speed setting until fully combined. Add the remaining powdered sugar and continue to mix on low until fully incorporated.
Use a food processor to grind the freeze-dried blueberries into a fine powder. Then, add the freeze-dried blueberry powder to the frosting and mix on low speed until well incorporated.
Add the heavy cream, vanilla extract and salt and mix on low speed until combined. Scrape the bottom and sides of the bowl occasionally to ensure the ingredients are well mixed.
Increase the speed on the mixer to medium and whip the buttercream for about 2 to 3 minutes until it is smooth and creamy. Turn the mixer to low speed and mix the buttercream for several minutes to remove any air bubbles.
Optional: To smooth out the buttercream, heat 1 cup of the frosting in the microwave for 15 seconds. Pour the melted frosting back into the mixing bowl and mix the frosting on low speed until the buttercream is super smooth and creamy.

Fill a piping bag fitted with a Wilton 1M piping tip with blueberry buttercream frosting. Pipe a generous swirl of the blueberry buttercream onto the cooled lemon cupcakes. Decorate the cupcakes with lemon slices and fresh blueberries.

Storing & Serving:

Room temperature: Store the cupcakes in an airtight container at room temperature for 2 days.
Refrigerator: Store the cupcakes in an airtight container in the refrigerator for 2 to 3 days. Serve at room temperature for the best taste and texture.
Storing note: I recommend adding the lemon slices and fresh blueberries before serving to prevent the fruit from drying out or expelling liquid.

Note: Metric conversions and nutritional information are calculated automatically. I cannot guarantee the accuracy of this information.