2 1/2 cups granulated
1/2 teaspoon ground cinnamon
1/4 cup hot water
3 cups whole milk
3 egg yolks
1 teaspoon vanilla extract
Preheat oven to 300 degrees.
Combine cinnamon with 2 cups granulated sugar in a saucepan over medium heat. As the sugar begins to melt, stir often until all sugar has dissolved and mixture has turned light brown. Add water to pan and stir until smooth. Pour about 1/4 cup sugar mixture into each of six 6-ounce ramekins. Swirl the sugar around the inside edge of each of the ramekins. Arrange the ramekins in a 9x13-inch roasting baking pan.
Heat milk in a saucepan over medium heat until it starts to bubble.
Whisk together eggs, egg yolks, vanilla, and remaining 1/2 cup sugar in a large bowl. Mix until sugar has dissolved.
When milk starts to bubble remove it from the heat. Pour about 1/4 cup of hot milk into the egg mixture while stirring. This will temper the eggs so they don't cook while adding the rest of the hot milk. Slowly add the remaining milk while mixing.
Fill the ramekins to the top with the custard mixture. Remove any foam from the top of each ramekin. Add water to the roasting pan to about halfway up the sides of the ramekins. Place a piece of parchment paper over the ramekins and bake for 75 to 90 minutes or until custard is firm and a knife inserted into the middle of the custard comes out clean.
Cool flan and cover each one with plastic wrap. Chill thoroughly before serving. To serve cut around the inside edge of the ramekin with a knife, then turn the flan over onto a plate. The caramelized sugar will spill down over the edges of the flan.
NOTESTo make chocolate flan, simply add 1 cup semisweet chocolate (chips or baking chocolate, broken into chunks) to the simmering milk. Stir until the chocolate melts and is evenly incorporated. Follow the recipe for plain flan to finish.