Step one

Line a 13 by 9-inch pan with aluminum foil, making sure it extends over the sides. Very lightly spray or butter the foil.

Step two

To make the crust, combine the flour, butter, brown sugar, and salt in a food processor fitted with a metal blade. Pulse until the butter forms pieces the size of small pebbles, 20 to 30 seconds. Pour the crust crumbs into the prepared pan and press down to form an even layer. Cover and refrigerate for at least 30 minutes, or up to overnight.

Step three

Preheat the oven to 350°F.

Step four

Bake the crust until golden, about 25 minutes. Set aside to cool.

Step five

While the crust is cooling, make the filling. Combine the cashews, sesame seeds, and salt in a bowl. Mix well and set aside.

Step six

Melt the butter in a saucepan over low heat. Add the granulated and brown sugars and honey and cook over medium heat, whisking constantly, until the sugar dissolves and begins to turn to caramel, forming large bubbles and thickening, or reaches 240°F on a candy thermometer.

Step seven

Remove from the heat and whisk in the cream and vanilla. Using a rubber spatula, mix in the cashew mixture until well combined.

Step eight

Pour the filling on top of the baked crust in an even layer. Return the pan to the oven and bake until the caramel bubbles along the sides of the pan only and the center is still liquid, 26 to 28 minutes. The filling will appear unbaked. It is very important not to overbake. The filling will set up as it cools.

Step nine

Set aside to cool completely and then cover and refrigerate overnight.

Step ten

Lift the foil out of the pan to remove the bars in one large block. Cut into thirty-six 11⁄2-inch squares.

Step eleven

Store in an airtight container in the refrigerator for up to 2 weeks.