Preheat oven to 350°F (177°C). Line a 12-count muffin pan with cupcake liners. This recipe makes around 20 cupcakes, so line a second muffin pan with more liners (or bake in batches).

Place 1/2 cup (80g) of the chopped strawberries in a food processor or blender. Pulse until strawberries are a chunky puree. You should have about 1/3 cup (80g). (Tip: If they’re getting stuck and not breaking down into a puree, add a splash of the milk to help move them along.) Set aside.

Set aside the remaining 3/4 cup (120g) chopped strawberries to be folded into the batter in step 6.

In a large bowl, whisk the cake flour, baking powder, and salt together. Set aside.

In a large bowl using a handheld or stand mixer fitted with a paddle attachment, cream the butter and sugar together on medium speed until light and fluffy, about 3 minutes. Scrape down the sides and bottom of the bowl with a silicone spatula as needed. (Here’s a helpful tutorial if you need guidance on how to cream butter and sugar.) Add the egg, egg whites, and vanilla and beat on medium-high speed until combined. Scrape down the sides and bottom of the bowl as needed. Beat in the sour cream. The mixture will look a little curdled and that’s normal and expected.

Add about half of the dry ingredients and half of the milk, and mix on low speed until incorporated. Add the remaining dry ingredients and remaining milk, as well as the strawberry puree, and mix until just combined. Do not over-mix. The batter will be creamy and slightly thick. Fold in the chopped strawberries.

Spoon batter into cupcake liners, filling only about 3/4 full. Bake for 21–24 minutes or until the tops of the cupcakes spring back when gently touched and a toothpick inserted in the center comes out mostly clean with just a few moist crumbs.

Allow to cool in the pan for 5–10 minutes, then transfer to a cooling rack. Allow the cupcakes to cool completely before frosting.

Using a food processor or blender, process the freeze-dried strawberries into a powdery crumb. You should have about 1/2 cup. In a large bowl using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the butter on medium-high speed until creamy, about 2 minutes. Add confectioners’ sugar, strawberry powder, cream, and vanilla. Beat on low speed for 30 seconds, then increase to high speed and beat for 2 minutes. Taste. Beat in a pinch of salt if frosting is too sweet.

Frost cupcakes as desired. I used piping tip Ateco #826. Garnish frosted cupcakes with fresh strawberries, if using.

Cover leftover cupcakes tightly and store in the refrigerator for up to 3 days. I recommend a cupcake carrier for storing and transporting decorated cupcakes.