Preheat your oven to 350°F (175°C) and prepare a 9x13 inch baking pan by greasing it or lining with parchment paper.

In a mixing bowl, beat the softened butter until light and fluffy, about 2-3 minutes. Gradually add granulated sugar and continue beating until airy and pale.

Add egg whites and whole egg one at a time, mixing well after each addition to create a smooth batter.

Gently mix in the whole milk, strawberry gelatin powder, and vanilla extract until just incorporated.

In a separate bowl, sift together flour, baking powder, baking soda, and fine sea salt. Gradually add this to the wet mixture, mixing gently.

Pour the batter into the prepared pan and bake for 20-25 minutes or until a toothpick comes out clean.

Cool the cake in the pan for 15-20 minutes, then invert it onto a wire rack to cool completely.

Prepare the buttercream frosting by beating softened butter until smooth, then gradually mix in heavy cream, vanilla extract, and confectioners' sugar until light and fluffy.

For the crunch topping, combine crushed Golden Oreos and freeze-dried strawberries, then drizzle in melted butter.

Once the cake is cool, frost the top generously with the buttercream and sprinkle the crunchy mixture evenly over it.

Chill the assembled cake in the refrigerator for at least 30 minutes before serving to allow the flavors to meld.