• Preheat oven to 350°F (177°C). Line a 12-count muffin pan with cupcake liners.

Make the cupcakes:

• a. Sift together the flour, cornstarch, baking powder, and salt in a large bowl. Set aside.
• b. In a medium bowl, beat the egg whites on high speed until soft peaks form, about 2-3 minutes. Set aside.
• c. In a large bowl, cream together the butter and sugar until light and fluffy, about 3-4 minutes. Beat in the egg yolk and vanilla extract until combined.
• d. Gradually add the dry ingredients to the wet ingredients, alternating with the milk, and mixing until just combined. Do not overmix.
• e. Fold in the egg whites, 1/3 cup strawberry puree, and finely chopped strawberries.
• f. Fill cupcake liners halfway with batter.
• g. Bake for 20-24 minutes, or until a toothpick inserted into the center comes out clean.
• h. Let the cupcakes cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.

Make the frosting:

• a. In a food processor or blender, grind the freeze-dried strawberries into a fine powder.
• b. In a large bowl, beat the butter on medium speed until light and fluffy, about 2 minutes.
• c. Gradually add the confectioners' sugar, strawberry powder, cream, and vanilla extract, beating until smooth and creamy.
• d. Add more confectioners' sugar if the frosting is too thin, or more cream if it is too thick. Add a pinch of salt if the frosting is too sweet.

Frost the cupcakes:

• a. Once the cupcakes are completely cool, frost them with the strawberry buttercream frosting.
• Enjoy!