Put the cream back in the fridge for about 30 minutes for caramel to set and become crunchy, and the cream cold again.
Reheat crust a few seconds before serving your guests with the perfect crème brulée: cold cream with a fine layer of hot crunchy caramel.
Remarks
As I said, the perfect crème brûlée (for me) is a soft and cold cream with a thin hot, brown and crunchy crust. Here are some tips:
Pre-cook the cream a little in the pan before putting into dishes, it will be less liquid, so the black grains of vanilla will be evenly mixed in the cream and not sink to the bottom. If you do this, reduce the oven cooking time to about 15 minutes.
Proceed in two stages: burn the creams and refrigerate for about half an hour to cool. Just before serving, re-heat them with the blowlamp for just a few seconds.
It's easier to get a good crust if you use white sugar rather than brown, but it's a matter of taste.
If you do not have a blowlamp, you can try using your grill: put creams in the grill pan (or deep solid baking sheet), add cold water to half the depth of the dishes, and put under grill for just one or two minutes (maximum) to caramelize sugar. Cold water is there to protect cream against the heat, but it's very difficult because the grill is always too hot.
Some different flavours:
Crème brûlée with almonds: add 20 g ground almonds to the milk before heating, and add 3 drops of almond extract to the cream before pouring into dishes.
Mint and chocolate crème brûlée: add a handful of mint leaves (cut roughly with scissors) to the milk. Proceed as usual, but when burned and cooled, put a small layer of melted chocolate onto the brown crust, put back in the fridge for a few minutes until the chocolate sets.
Pear and maple syrup crème brûlée: dice pears like for verre façon "Belle Hélène", put these into dishes before adding cream and proceed as usual. Surprise your guests - don't tell them what's in your Crème brûlée!