Mix butter and sugar until creamy. Add the vanilla extract and eggs one at a time. Do not add the next one until the first egg is fully incorporated.
Then add self-rising flour and salt, mix until these dry ingredients are incorporated into the batter.
Take a cupcake baking pan and place the cupcake liners in the cavities, divide the batter between the cups. I personally do this with an cookie scoop/ice cream scoop. It works easily and you can distribute the batter nicely evenly this way.
Bake the cupcakes for about 18 minutes at 180 °C/ 350 ℉ (conventional).
Let them rest in the baking tin for a while before letting the cupcakes cool completely on a wire rack.
Use an apple corer to remove some cake from the center of each cupcake. Do not make the hole all the way to the bottom.
Fill each cavity in the cupcakes with strawberry jam.
To make the mascarpone frosting put whipping cream, vanilla sugar and mascarpone in a bowl. Mix briefly on a low setting and then on a high setting until the mixture is firm.
Lastly, add the strawberry jam and mix it into the mascarpone frosting on a low setting.
Fill a piping bag with star shaped nozzle with the strawberry mascarpone frosting and pipe nice swirls on the cupcakes.
Decorate each cupcake with half a strawberry to complete your strawberry cupcakes.
How to store
Keep in a sealed container for 3-4 days in the refrigerator.