In the bowl of your hand or stand mixer, place the mascarpone cheese. Afterward, beat for two minutes at medium speed until smooth.
After that, make sure to turn the mixer on low speed, gradually add the powdered sugar until fully incorporated. Increase speed by medium once the powder combines with the cheese and mix for a minute. Then, constantly utilize a rubber spatula to scrape the bowl.
Then, mix in the vanilla extract and turn the mixer on medium-high speed.
Adding vanilla extract
Now, gradually pour the heavy cream into the mixer. I recommend you pour in by part to avoid unnecessary splattering. Again, do not forget to scrape the bowl.
As the mixture mixes with the heavy cream, it will start to take shape and thicken. Be careful, and do not over-mix the heavy cream.
Once the frosting takes shape, turn the mixer off. After that, perform a whisk test by dunking the whisk attachment into the frosting and flipping it upside down. The frosting should keep its shape to form a nice peak. However, if it does not, continue mixing the frosting at high speed with thirty seconds intervals.
Finally, if you achieved the desired peak, transfer the filling in a piping bag with a piping tip. You may refrigerate for a few minutes or use it as a filling immediately.