Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking pan with butter or line it with parchment paper.

Cream together the softened unsalted butter and granulated sugar in a large bowl using an electric mixer for 3-5 minutes until pale and fluffy.

Incorporate the egg whites and whole egg one at a time, mixing well. Add the whole milk, strawberry gelatin powder, and vanilla extract, mixing until smooth.

Sift together the all-purpose flour, baking powder, baking soda, and fine sea salt in a separate bowl. Gradually add to the wet mixture, mixing gently until no flour streaks remain.

Pour the batter into the prepared baking pan, smoothing out the top evenly.

Bake for 20-25 minutes, until a toothpick inserted in the center comes out clean. Cool in the pan for 15-20 minutes before transferring to a wire rack.

Beat the softened unsalted butter for the frosting in a medium bowl until creamy, then gradually incorporate the heavy cream, vanilla extract, and a pinch of salt. Gradually add confectioners' sugar until fluffy.

Blend the Golden Sandwich Cookies in a food processor until crumbly. Mix these crumbs with the lightly crushed freeze-dried strawberries and melted butter until well combined.

Once the cake is cooled, generously frost the top with buttercream and sprinkle the crunch topping evenly over the frosting.

Chill the completed cake in the refrigerator for at least 30 minutes before serving.