Step 1

Line bottom and sides of an 9-inch square baking pan with parchment paper. (Related: Kitchen Tip: Lining Pans with Parchment)

Step 2

Bring cream, butter, and salt to a boil in a small saucepan, then remove from heat and set aside.

Step 3

Combine sugar, corn syrup, and water in a 4-quart heavy saucepan.

Step 4

Boil, without stirring but gently swirling pan, until mixture is a light golden caramel and sugar is dissolved.

Step 5

Carefully the cream mixture (mixture will bubble up) and simmer, stirring frequently, until caramel registers 248°F on thermometer, 10 to 15 minutes.* (see note below regarding altitude)

Step 6

Remove from heat and stir in the vanilla extract.

Step 7

Let cool slightly while you prepare the chocolate. It should still be pourable for assembly. If it has cooled too much that it is no longer pourable, then slightly rewarm over low heat.

Step 8

Place a medium saucepan filled about half way with water over medium-low heat on your stove. Allow the water to come to a simmer.

Step 9

Add the chocolate to a heat-proof bowl (or the top portion of a double boiler if you have one), and place the bowl on top of the saucepan.

Step 10

Turn the heat under the pan off.

Step 11

Let the chocolate sit in the bowl over the saucepan of hot water until in begins to melt around the edges.

Step 12

Then, stir the chocolate until smooth, while monitoring the temperature using a candy thermometer.

Step 13

Tempered chocolate will quickly solidify as it cools, so you'll need to move as quickly as possible.

Step 14

You can tell that it has gotten too cool by its appearance, which will become matte and thicker when you stir it.

Step 15

If the chocolate gets too cool, just gently rewarm it to the appropriate temperature.

Step 16

Make sure to stir and scrap up the sides and bottom of the bowl and mix the chocolate throughout.

Step 17

Once rewarmed, remove the chocolate from the heat and keep stirring to evenly distribute the heat.

Step 18

Pour half of the melted milk chocolate in the prepared parchment lined pan.

Step 19

Spread the chocolate into a smooth, even layer.

Step 20

Sprinkle 3/4 cup of the rice crispies evenly over the chocolate.

Step 21

Pour the caramel evenly over this layer.

Step 22

Then, sprinkle the remaining 3/4 cup of rice crispies over the caramel layer.

Step 23

Pour and spread the remaining milk chocolate on top.

Step 24

Allow the mixture to cool until it has completely hardened. This will take several hours, so it is best prepared the day before you plan to cut and serve.

Step 25

Once cool, cut into 1.5 inch x 1.5 inch squares.