Preheat oven to 350 °F (177 °C) and grease a 9" cake pan. Set aside.
In a bowl of a stand mixer, add the sugar and egg whites and beat with whisk attachment until stiff and glossy.
Gently add the yolks, one at a time, to the egg white mixture until all is incorporated.
Remove the bowl from the stand then gently fold in milk, vanilla extract, and cake flour (in that order) with a spatula until combined. Gently fold in the melted butter.
Pour the cake batter into the prepared pan and bake for 25-30 minutes or until cake is golden brown. When pressed, the cake should spring back.
Cool the cake in the pan on a wire cooling rack completely.
While the cake is cooling, make your stabilized whipped cream.
In a small pot, sprinkle the gelatin over the 4 teaspoons of cold water and let sit for 5 minutes. Do not stir. Once it's been 5 minutes, you may stir it and put it on low heat, constantly stirring, to dissolve the gelatin. Once dissolved, set aside.
In a bowl of a stand mixer, whisk the heavy cream, sugar, and vanilla extract until it has thickened. Then, slowly add in the gelatin mixture and beat until fluffy.
Once your cake has cooled, you may begin assembling it. With a sharp knife, slice the cake in half horizontally into 2 layers.
Spread a thin layer of the whipped cream on the bottom half of the cake layer and then top with strawberries. Gently spread another thin layer of whipped cream on top of the strawberries then place the other half of the cake layer on top. With the remaining frosting, frost the entire cake. When done, top with the remaining strawberries.
Serve immediately or put in fridge for a few hours and then serve.
I do not recommend this sitting for more than 2 days as it will harden a little and doesn't stay as spongy and light.