Position a rack in the center of the oven and heat the oven to 325°F. Arrange eight 6-ounce ramekins in a large roasting pan.
Make the Basic Caramel according to the directions, but cook it another 30 seconds or so to a medium-dark amber (pictured below). Immediately pour the hot caramel into the bottoms of the ramekins, portioning it equally. Quickly and carefully swirl each ramekin to coat the bottom evenly and coax the caramel about 1/2 inch up the sides of the ramekins. Set aside to let the caramel harden.
Fill a teakettle with water and bring to a boil. Combine the milk, cream, sugar, and salt in a heavy-duty 3-quart saucepan and bring to a simmer over medium-high heat, stirring occasionally. Remove the pan from the heat.
Whisk the eggs, yolks, and vanilla in a medium bowl and then slowly add the hot milk mixture, whisking constantly. Strain the mixture through a fine sieve into a 1-quart heatproof measuring cup. Portion the custard among the ramekins.it should just about fill each one. Pour the hot water from the kettle into the roasting pan until it comes one-third to halfway up the sides of the ramekins (be careful not to splash water into the custards). Bake the custards in the water bath until the edges are set but the centers still jiggle slightly when gently shaken, 30 to 35 minutes. If the centers are more wavy than jiggly, cook them a bit longer. Rotate the pan halfway through if the custards appear to be baking unevenly.
Carefully transfer the ramekins to a wire rack and cool completely. Cover each ramekin with plastic wrap and refrigerate for at least 12 hours, or up to 3 days.
To serve, run a small knife around the edge of each ramekin to loosen the custard. Quickly invert each custard onto a plate. If it doesn't release right away, gently shake the ramekin from side to side a few times to help it out.
Orange Crème Caramel: Add 1 tablespoon finely grated orange zest (from 1 medium orange) to the milk mixture before heating it.
Espresso Crème Caramel: Add 1 tablespoon instant espresso powder (such as Medaglia d'Oro brand) to the heated milk mixture.