Preheat the oven to 350°F (175°C). Prepare some boiling water.

Combine cream and 5 teaspoons sugar in a saucepan over medium heat. Cook, stirring occasionally, until small bubbles appear around the edges of the pan, approximately 5 to 6 minutes. Remove from the heat and set aside.

Beat egg yolks and vanilla in a bowl until smooth and light. Gradually pour hot cream mixture into the egg yolks while whisking continuously. Strain the mixture through a fine sieve into a bowl. Divide evenly among four 3-ounce ramekins.

Arrange ramekins in a baking pan and place on the middle shelf of the preheated oven. Pour boiling water into the baking pan until halfway up the sides of the ramekins. Cover the pan loosely with aluminum foil.

Bake until custard is just set and jiggles when gently shaken, about 25 minutes. Carefully remove from the oven and let cool to room temperature, approximately 30 minutes. Transfer to the refrigerator to chill for 2 to 3 hours, or overnight.