For the White Cake:Preheat the oven to 350 degrees (180 degrees F). Grease and line two 6 inch cake pans with parchment paper.
In the bowl of a stand mixer fitted with the paddle attachment, mix the flour, sugar, baking powder, and salt.
Cut up the butter into small cubes and add to the dry ingredients. Mix on low speed until it resembles wet sand.
Add the oil, milk, yogurt, and vanilla, and mix until just combined.
In a separate bowl, whip the egg whites to stiff peaks. Gently fold it into the batter with a rubber spatula until just combined.
Pour batter into the prepared pans and bake for 26-28 minutes or until a tooth pick inserted comes out clean.
Cool completely before frosting.
For the Mascarpone Frosting:In the bowl of a stand mixer fitted with a whisk attachment, combine the heavy cream, mascarpone, and sugar.
Whisk on low speed until combined, then turn up to medium high speed until thick (only about 30 seconds).
For Assembly:Spread a thin layer of frosting on the first cake layer, then pipe a wall of frosting around the edge.
Add 1-2 layers of sliced strawberries.
Pipe another wall of frosting around the edge and add another layer of strawberries.
Top with the second cake layer and spread a thin layer of frosting all around for the crumb coat. Place in the fridge for about 30 minutes.
Take the cake out of the fridge and decorate as desired. To achieve the same petal top design as in the photos, place the remaining frosting in a piping bag fitted with a medium round piping tip (I used Ateco 807). Start at the edge and layer them as you move inward. Add a halved strawberry in the center and sprinkle with raw cane sugar.