Infuse Milk: Heat milk until just below boiling. Remove from heat, add tea, and steep for 15–20 minutes.
4 tbsp Earl Grey leaves, 2 cups milk
Strain and Measure: Strain the milk, squeezing out the leaves to extract flavor, and top up the milk to 2 cups.
Heat Milk Mixture: Combine milk, vanilla, and sugar in a clean pot. Heat to a gentle boil, stirring occasionally.
1 teaspoon vanilla extract, 7 tablespoons sugar
Prep Yolks: While the milk heats, whisk yolks, cornstarch, and 2 tablespoons of the milk mixture (while it's still lukewarm) in a bowl.
4 egg yolks, 4 tablespoons cornstarch
Temper Eggs: Gradually whisk hot milk into yolk mixture in small additions to avoid curdling.
Thicken Cream: Return the mixture to the pot and cook over medium heat, stirring constantly, until thickened and bubbling (2–4 minutes).
Whisk Off Heat: Remove from heat and whisk for about a minute until smooth.
Add Butter: Stir in butter until fully melted and incorporated.
2 tablespoons unsalted butter
Taste and Adjust: Taste while hot and add sugar if needed.
Strain if Desired: Strain through a mesh sieve for extra smoothness.
Cool: Cover with plastic wrap touching the surface to prevent a skin. Cool at room temp for 30–60 minutes, then refrigerate.
Whisk and Use: Break up the chilled cream with a fork and whisk until smooth before using.