Preheat the oven to 350F/177C and line two, 8-inch (20-cm) cake rounds with parchment paper.
In a large mixing bowl, beat together softened butter, sugar and vanilla until fluffy. Add the egg whites or eggs and beat again until creamy and smooth. Using only egg whites yields a more 'white' cake; using whole eggs will give the cake a soft yellow color. Next, pour in the milk (I recommend using warm milk).
In a separate bowl, combine all the dry ingredients: flour, baking powder and salt. Sift the dry ingredients into the cake batter and whisk by hand to avoid over-mixing the batter.
To the finished batter, add the strawberry preserves and the strawberry emulsion. Fold the preserves gently into the batter, then divide it evenly between the two prepared pans. Bake the layers in the preheated oven for 28 to 30 minutes. Allow the layers to cool completely before assembling the cake.
For Strawberry Buttercream:
For the strawberry buttercream, place the softened butter into a mixer bowl and whisk on high speed for 5 to 6 minutes, until the butter is light and white in color. Add the confectioner's sugar and whisk again for a few minutes. Once the buttercream has reached the perfect consistency, add the strawberry preserves and emulsion. Whisk again but just until the strawberry is incorporated, about 20 seconds. Transfer 1 cup of the frosting into a pastry bag tipped with any star tip.
For Basil Filling:
The basil filling is best if used right away; I recommend waiting to make it until the layers are cooled. Place the basil and confectioner's sugar into a food processor. Pulse the basil and sugar together for a few minutes, until a thick paste forms. In a separate bowl, whisk the chilled heavy cream until stiff peaks form, about 4 minutes. Add the basil paste and whisk again for 20 to 30 seconds, until well incorporated.
Assembling the Cake:
To assemble the cake, use a long serrated knife to slice each layer in half, creating 4 layers total. Spread a few tablespoons of the strawberry buttercream onto each layer, then pipe a barrier ring of frosting around the edge of the layer. Fill the center with a generous amount of the basil whipped cream. Repeat this process for the remaining layer, then frost the outside with the remaining strawberry buttercream. Place the cake into the refrigerator to set while preparing the white chocolate glaze.
For the white chocolate ganache, combine the milk/cream, 1/2 cup of the chocolate and the shortening in a microwave-safe bowl or measuring cup. Heat for 1 minute, then stir until the chocolate is melted. Add the remaining 1/4 cup chocolate chips to help cool down the ganache. Allow the ganache to cool for about 15 to 20 minutes, until it's thick enough to pour onto the cake.
Pour the glaze over the chilled cake, nudging it gently over the side with a spatula. Garnish the top of the cake with fresh strawberries, dollops of cream and silver pearls. Keep cake refrigerated if not serving the same day. Remove the cake at least 1 hour prior to serving to allow the cake to thaw.