Vanilla cupcakes : 

1. Preheat the oven to 350°F / 180°C and line a standard cupcake tin with cupcakes liners.
2. In a medium bowl, mix and sift together all the dry ingredients, cake flour, baking powder and salt, then set aside.
3. Place the softened unsalted butter with the extra-fine granulated sugar in the bowl of your stand mixer fitted with the whisk attachment, and beat at high speed for 2-3 minutes until creamy and smooth.
4. Keeping the whisk running at medium speed, add the vanilla extract and eggs, then continue at high speed for around 2 minutes until you have a voluminous mixture.
5. Stir in the buttermilk, then the dry ingredients, using a spatula to avoid over-beating the mixture.
6. Fill the paper cups in the cupcake tin 3/4 full (use a standard ice-cream scoop to measure out the mixture). Be careful not to overfill, or the cupcakes will overflow during baking.
7. Bake the cupcakes in the preheated oven for about 13-15 minutes, without opening the oven door, until well done. (Check for proper baking by sticking a toothpick into the center of the cupcake; if it comes out clean, it's done).
8. Let the strawberry cupcakes cool slightly before removing from the cupcake tin and cooling completely on a cake rack.

Prepare the strawberry compote in advance and chill in the fridge until ready to assemble.

Mascarpone Frosting

1. Place the cold mascarpone cheese in a mediaum bowl with the cold heavy cream, powdered sugar and vanilla extract.
2. Beat at medium speed with an electric mixer for 3-4 minutes until firm and smooth (be careful not to overbeat, or it will slice and be grainy).
3. Fill a piping bag fitted with a decorating tip with all the mascarpone whipped cream and set aside in the fridge.

Assembly 

1. Using a Cupcake corer, scoop out the center of the cupcakes.
2. Fill the inside with the strawberry compote.
3. Decorate the top with mascarpone whipped cream and add a piece of fresh strawberry.
4. Place in the fridge for at least 1 hour before serving.