Ingredients for the cupcakes1 1/2 cups all-purpose flour 1/4 cup cornstarch 1 teaspoon baking soda 1/2 teaspoon kosher salt 1/2 cup (1 stick) unsalted butter 1 cup sugar 3 egg whites, room temperature 1 1/2 tablespoons lavender syrup 1/2 cup sour cream, room temperature 1/2 cup whole milk, room temperature
Ingredients for the buttercream3 cups confectioner's sugar 1 1/2 cups (3 sticks) unsalted butter 1/4 teaspoon kosher salt 1 1/2 tablespoons heavy cream 1 tablespoon lavender syrup Food coloring gel (violet and blue)
Directions for the cupcakes
- Preheat oven to 350 degrees F. and spray a heavy gauge cupcake pan with a non-stick cooking spray.
- In a medium bowl, whisk the flour, cornstarch, baking powder, baking soda, and salt together.
- In the bowl of an electric stand mixer, beat the butter on high speed until light and creamy. Add the sugar and beat on medium speed for 2 minutes, stopping to scrape the sides and bottom of the bowl after 1 minute.
- Add the eggs, one at a time. Then add the lavender syrup. Turn the mixer to medium-high speed and mix until combined. Add the sour cream and mix for 1 minute.
- Add the dry ingredients, mixing on low speed just until combined, then scrape the bottom and sides of the bowl.
- With the mixer on low speed, add the milk, stirring just until combined. Do not overmix.
- Spray each cup of a heavy gauge muffin or cupcake tray with a non-stick spray.
- Fill each cupcake cup about 2/3 full with batter, then bake for 20 minutes, or until a toothpick inserted in the center of a cupcake comes out clean.
- Transfer to a wire baking rack to cool for 10 minutes, release from pan, and cool completely before frosting.
Directions for the buttercream frosting
- In the bowl of an electric stand mixer, combine the butter and confectioner's sugar until smooth, about 1 minute.
- Add the salt, lavender syrup, and heavy cream, and mix 1 minute more.
- Divide the buttercream into two equally portioned bowls. Use a toothpick to add a very small dot of blue food coloring gel to one bowl and use a spatula to thoroughly mix. Add tiny dots of gel coloring until the desired shade of blue is achieved. Repeat with the violet gel coloring in the second bowl of buttercream.
- Fit a piping bag with a Wilton 1M or 2D star tip, fold over the bag exposing the bottom half of the bag, and fill it 1/2 full with equal amounts of the two colors of frosting, side by side.
- Pull the folded part of the bag up and over the frosting, twist, and on a small plate begin gently squeezing stars out of the bag with short, sharp motions. When both colors come out, it is time to begin frosting the cupcakes.
- Begin frosting around the perimeter of the cupcake and work the stars to the center until the cupcake is completely covered in hydrangea blossoms.
- Store the cupcakes in a cool dry place if eating the same day, or in the refrigerator to prevent the buttercream from melting.