Preheat the oven to 325°F.

Spray an 8-inch square pan with cooking spray. Line the pan with a layer of parchment paper covering the bottom and up 2 sides with a slight overhang. Spray the parchment paper.

Add the milk and butter to a small saucepan. Place the pan on low heat just until the butter melts. Don’t let the milk come to a boil or simmer. It should be warm, but not scalding hot, 105 to 115°F. Set aside.

In a large bowl using a hand mixer, beat the egg whites on medium-high speed until they form stiff peaks, about 4 minutes.

In another large bowl, add the egg yolks, sugar, vanilla extract, and salt. Beat on high speed until the mixture is pale and creamy, about 2 minutes.

Add the flour to the egg yolk mixture and beat on low speed until combined.

With the mixer running on low speed, pour in the warm milk and butter, a splash at a time. Once half of the milk mixture has been incorporated, pour in the rest, and whisk to combine.

Add the beaten egg whites and whisk gently until no large lumps remain.

Pour the batter into the prepared pan. Gently lay the sliced strawberries over the top of the cake.

Bake until the top is golden brown, the cake has begun to pull away from the sides of the pan, and the center has a slight jiggle when the cake is gently shaken, about 50 minutes.

Remove the pan from the oven and set it on a wire rack to cool for 30 minutes. Place the pan in the fridge and chill for at least 1 hour before serving.

In a small bowl, whisk together the powdered sugar and freeze-dried strawberry powder. Use a small sieve to dust the top of the cake with the powdered sugar mixture, then cut into squares.