1. In a small saucepan, bring milk, cream, and vanilla bean to a boil.
2. Remove vanilla bean. With a sharp knife, cut in half lengthwise and scrape the seeds into the hot milk.
3. In a medium bowl, whisk together sugar, cornstarch, and egg yolks.
4. Slowly pour hot milk into the sugar mixture, whisking vigorously.
5. Return mixture to the saucepan and continue cooking, mixing constantly, until it thickens.
6. Remove from heat, add butter, and mix until combined. Let cool.
7. In an electric mixer, beat heavy cream until stiff peaks form. Gently fold into the cooled cream.
Can I make this in advance? Does it freeze well?
Yes the cream cups for sure freeze well. The Tuile Balls should also freeze well but keep them separate.