Step 1

Fill a small saucepan halfway with water and bring to a simmer over medium heat.

Step 2

In a large bowl, whisk together the egg yolk and sugar. Add the bowl over the simmering pot of water and continually mix until sugar has fully dissolved or until the mixture is creamy and a pale yellow color, about 3 minutes.

Step 3

In another bowl, use an electric hand mixer to cream together the mascarpone cheese, half and half, and vanilla extract for 2 minutes, until soft peaks form.

Step 4

Add the egg yolk and sugar mixture and cream together until soft peaks form, about 2 minutes.

Step 5

Add the brewed Thai tea to a shallow bowl. Working one at a time, dip the ladyfingers into the tea, holding them for 5 seconds to soak. Layer them in a 9-inch square baking dish.

Step 6

Spread a layer of the mascarpone cream and repeat the layering process two more times until you finish with the mascarpone cream on top.

Step 7

Cover the tiramisu with plastic wrap and chill for at least 2 hours.

Step 8

Serve and top it with cooked boba pearls if desired.

Step 9

Enjoy!