In a saucepan, combine the milk, cream, and vanilla. Bring the mixture to a gentle boil, watching carefully to prevent it from overflowing. Turn off the heat as soon as it begins to boil.
Add the sugar and stir until fully dissolved.
Sprinkle the gelatin powder into the warm mixture while whisking continuously to avoid any lumps.
Pour the mixture into individual molds or ramekins, then let them cool at room temperature for about 30 minutes.
Note: A thin skin may form on the panna cotta surface. This can be removed with a spoon while still in liquid form if desired, although it is not necessary.
After 30 minutes, refrigerate the panna cottas for at least 4-6 hours or overnight until set and chilled.
How to Remove Panna Cotta from Molds:
Prepare a bowl of hot water.
Take each panna cotta from the fridge and dip the mold in hot water for a few seconds.
Gently invert the panna cotta onto a serving plate, remove the mold, and serve.