For your caramel, combine your sugar and water in a large pot. Use the back of a spoon or a spatula to gently cover all the sugar with the water. It should look like wet sand. Make sure no sugar is stuck on the sides of the pot (not covered in water), or it will burn

In another small pot, add your heavy cream

Place the pot with water and sugar on the stove over high heat. Do not stir!

When your sugar-water mixture starts to turn lightly brown (straw-colored) around the edge, place your pot with heavy cream on another burner over medium-high heat and bring it to a scald (a rim of bubbles) but not boiling

Keep a close eye on your sugar/water mixture as it turns light brown. Once you see brown around the edges, keeping your pot flat on the stovetop, lightly swirl it to move the browning around and evenly color your liquid. Once it is the color of light wood, immediately remove it from the heat (it will continue to brown in the pan) and place it on your counter

Carefully stream your scalding heavy cream into your pot with the browned sugar. It will bubble; don’t be alarmed, this is why we use a large pot, to allow the bubbles to subside before continuing

Add in one piece of your lightly softened butter at a time, whisk in, and repeat until all is incorporated

Sprinkle in your sea salt, whisk in, and allow your caramel to cool while you prep your cookies

For your cookies, cream together your brown sugar, butter, and vanilla in a bowl. Beat for a minute on a medium speed until light and fluffy

In a separate bowl, whisk together your flour, cocoa powder, cornstarch, and salt

Pour your dry ingredients into your butter mixture, stir together with a spatula until mostly combined, and then beat with your mixer until fully mixed in. Cover your bowl and pop it in the fridge for 30 minutes to let the flavors meld and allow the flour to absorb into the dough

Preheat your oven to 350°F and line a baking sheet with parchment paper

Once set, roll 2 tablespoons of dough at a time into a ball. Place on a cookie sheet about an inch apart. Depending on the size of your cookie sheet, you’ll have to at least do two bakes (half the balls first, bake, and then the next)

Once your dough is rolled, use your thumb to press an indent into the center of each cookie; be careful not to push all the way through. If needed, use your fingers to press the edges back together if they crack

Bake for 15 minutes. At the halfway mark, remove your cookies from the oven and use a teaspoon to re-form the indent, as it will have likely puffed up a bit as the cookies baked. Rotate your tray and place the cookies back in the oven for the remainder of their baking time. You want your shortbread to have a lovely chew in the middle, so don’t overbake these!

Cool on the tray for 2 minutes, then transfer to a wire rack to cool completely

Spoon your caramel into each of your thumbprints and top with your crushed pretzels

Allow to set for an hour, to cool your caramel and make sure it doesn’t run right out

Enjoy!