Caramel Fudge Bars with Cinnamon Shortbread Crust

Preheat your oven to 375 degrees. Spray a 9 x 13 inch baking pan lightly with oil. Line it with parchment paper, so that the paper hangs over two sides. This will make it easier to air lift the whole thing out later, if you like.

Make the cinnamon shortbread crust

Put the butter, brown sugar, vanilla, cinnamon, and salt in the bowl of your mixer. Beat on high until you have a homogeneous paste. Scrape down the sides of the bowl with a spatula. Turn it over a few times with your spatula to be sure you don’t have stray sugar in the very bottom of the bowl.

Toss in the flour and mix a little with your spatula to get the dough started. Then mix on high for maybe 30 seconds, until the dough just comes together. Transfer the dough to your prepared pan.

Smoosh the dough down with your hands, spreading it out so that it fills the entire pan. Next, prick the dough all over with a fork. The holes will let steam out as the shortbread cooks, which will keep your cookie crust from developing big bubbles.

Pop the pan into your preheated 375-degree oven. Bake for 15-20 minutes until golden brown and firm to the touch. Set the pan aside to cool to room temperature.

Make the fudge topping
Put the yolks in a large mixing bowl. Beat them well, then set them aside while you deal with the cream. Put the cream and dulce de leche in a medium-sized, heavy-bottomed pot. Set it on the stove over medium heat. Whisk gently to break up the dulce de leche. Keep whisking until all the dulce de leche has melted and the mixture is uniform.

Bring it up to a simmer, whisking often. As the mixture gets hot, it will thicken. When it comes to a simmer, remove the pot from the heat. Pour about half of the hot mixture into the beaten egg yolks in a slow, thin stream. Whisk constantly. You want to temper the egg yolks (raise their temperature gently) so they don’t scramble.

When you’ve poured in about half the mixture, add the rest to the bowl, whisking continuously.

Next, pour the contents of your bowl back into the pot. Pour through a strainer, if you like, to catch any errant bits of egg that may have cooked solid. Clip a candy thermometer to the inside of your pot and set it on the stove over medium-high heat. Whisk continuously. Cook like this until the mixture reaches 175 degrees and has thickened.

When it’s ready, remove the pot from the heat and toss in the chopped chocolate. Whisk to combine. The chocolate will start to melt immediately. Keep whisking until all the chocolate has melted.

Pour the chocolate mixture on top of your cooled shortbread crust. Spread it out with a spatula so that it’s relatively even. Let it cool to room temperature on the counter. Then pop it into the fridge uncovered to chill completely, about 3 to 4 hours. (This is the hard part, where you wait.)

When the bars are ready to cut, the fudge topping will be pretty firm. Slice with a knife dipped in hot water, wiping it down in between each cut.