Heat the sugar over medium-high heat in a saucepan until it reaches a dark, golden brown color. Do Not Stir!! Swirl the pan occasionally, but do not stir.
Divide the caramel between (6) 6-ounce ramekins. Set aside and allow to cool.
Create the Custard
Heat the milk and cream in a medium saucepan. Stir in the sugar and sea salt and heat until the sugar dissolves. Remove from heat and set aside.
Lightly beat the eggs in a small bowl. SLOWLY add 1/4 cup of the hot cream mixture to the eggs while whisking to raise the temperature of the eggs. {this is called tempering the eggs}.
Slowly add the the egg mixture into the heated cream mixture, whisking to combine. Stir in the Kahlua or flavoring of your choice.
Pour the custard mixture over the caramel in the ramekins. Gently tap the ramekins on the counter to remove the air bubbles, or pop them with a toothpick. Tightly cover the ramekins with aluminum foil.
Stacking the Ramekins in the Instant Pot
Place a trivet at the bottom of the liner of your Instant Pot and pour in 1 cup of water. Set (3) ramekins on the trivet, then place a riser on top of the ramekins. Place the remaining ramekins on top of the riser.
Secure the lid and turn the vent knob to the “Sealing” position. Press the Manual button and adjust the time to 9 minutes using the = and – buttons.
When the pot beeps, allow the pressure to release naturally, it will take about 10 minutes.
Carefully remove the ramekins from the pressure cooker and place them on a wire rack to cool.
Once they have cooled, put the foil back on the ramekins or use plastic wrap to cover them. Place them in the refrigerator to chill for at least 3 hours, but overnight is better.
To unmold the Flan
Run a thin knife around the inside of the ramekin and carefully invert onto a rimmed serving plate and serve.
Notes
Watch your caramel closely!! It will go from a gorgeous mahogany color to burnt in a blink of an eye!
You can use any type of heat-proof ramekin to make your Instant Pot Kahlua Flan. I used two different glass custard cups, but ceramic ramekins will work as well.
The riser/ tall trivet does not stand on the bottom, it is resting on top of the first layer of ramekins to keep the second layer steady and keep them from tipping over.
Add 1 Tablespoon of pure vanilla extract for an alcohol-free treat.
Substitute any liqueur to change up the flavor. Baileys, Cointreau, or Amaretto would be excellent choices.
If you do not want to use foil, you will need to find some kind of silicone cover that you can cover each ramekin with.