Step 1

Combine all the ingredients except for the vanilla in a medium, heavy-bottomed sauce pan.

Step 2

*You can leave out the corn starch if you want to. You will need to make sure that you remove the custard from the heat before it comes to a boil though. The starch buys you some time if it does boil. Using the cornstarch will also give you an extremely thick base. You may have to check your ice cream maker and stir with a spatula a few times during churning to make sure it freezes evenly.

Step 3

Cook, whisking constantly, over medium to medium-high heat, until the mixture thickens. If not using cornstarch, shoot for 185F. If using corn starch, allow to boil (still whisking constantly) for about 10 seconds. Evaporated milk tends to stick and scald very easily since it has a relatively low water constant. You really will need to whisk constantly and regulate your heat if you feel it sticking on the bottom of the pan. I normally cook all my custards over high heat, but even I dialed it back to a dull roar to be on the safe side.

Step 4

Immediately strain through a fine mesh strainer into a bowl with the vanilla. You will need to push the thick custard through with a silicone spatula.

Step 5

Stir well to incorporate the vanilla.

Step 6

Chill in an ice bath or cover with plastic wrap (press it directly on the surface of the custard) and put in the freezer to chill quickly or refrigerate for 8-12 hours. Make sure your base is very cold, no more than 40F, before churning.

Step 7

Line a rimmed baking sheet with Silpat or parchment that you've lightly coated with pan spray. (Silpat is preferred here)

Step 8

Place the baking sheet on two trivets or a folded towel to protect your counter.

Step 9

In a small, heavy-bottomed sauce pan, heat the sugar and water over medium heat. Stir to dissolve the sugar, and bring to a boil.

Step 10

Cover the pan with a lid and let boil for a minute or two to wash down any sugar crystals that might be clinging to the side of the pan.

Step 11

Remove the lid and allow to boil until the caramel starts to turn golden. Swirl the pan gently to make sure the sugar caramelizes evenly.

Step 12

Continue to heat until the sugar is a dark amber color and has started to smoke just a bit. I know mine is ready when it starts to sting my eyes. Make sure to take it this dark. If you don't, it will be too sweet and not provide a slight bitterness in contrast to the sweet, creamy flan base.

Step 13

Immediately pour the caramel onto the prepared pan.

Step 14

Holding the pan with a towel or oven mitts, tilt the pan to allow the caramel to flow into a thin sheet. You have about 1-2 minutes to get it as thin as you can by tilting before it becomes too hard to flow.

Step 15

Allow to cool until hardened.

Step 16

Churn the ice cream base according to manufacturer's instructions. Especially if you used corn starch in your base, you'll want to keep an eye on it and make sure the base is being churned evenly. I stirred every couple of minutes with a spatula.

Step 17

While the ice cream is churning, break up the caramelized sugar with a rolling pin or whatever hard thing is handy. Break it into fairly small pieces, no more than 1/2" or so.

Step 18

Once the ice cream is at soft-serve consistency, stir in the caramel "shards."

Step 19

Pack into a container and press plastic wrap directly on the surface of the ice cream. Put a lid on your container (if it has one).

Step 20

Freeze for several hours or overnight before scooping and serving.

Step 21

Enjoy in small portions--this is rich stuff!

Step 22

Once the base is frozen into the consistency of soft serve