First, get all of the caramel ingredients ready because everything needs to be mixed in while the caramel is still hot. Most importantly, the heavy cream must be at least room temperature, otherwise the caramel can seize up. If it’s too cold, pop it into the microwave to warm up beforehand.

Add the water and sugar to a heavy-bottomed saucepan. Gently stir to evenly mix, careful not to allow any of the sugar to slosh up against the sides of the pot.

Place over medium heat and allow the sugar to dissolve on its own. Do not touch.

Once the mixture turns completely clear and bubbling, sit and watch as it turns from clear, to light golden, to a rich amber. If the sugar is browning unevenly, gently nudge the sugar around in the pot to evenly distribute the darker sections.

When the sugar turns evenly amber, immediately remove from the heat and whisk in the butter.

While gently whisking, slowly pour in the heavy cream and mix until smooth.

Now whisk in the vanilla and salt.

Return to medium heat and bubble for about 2 minutes.

Then remove from the heat and whisk in the flour.

Set the pot of caramel off to the side while we make the cookie dough.

Preheat the oven to 350F and grease and line all sides of an 8×8 baking dish with parchment paper.

In a medium bowl, whisk together the oats, flour, baking powder, and salt. Set aside.

In a large mixing bowl, mix together the softened butter and dark brown sugar until smooth. This can be done by hand with a wooden spoon, or with an electric mixer.

Now mix in the egg, egg yolk, and vanilla.

Pour in the dry ingredients and mix to combine. Just before the flour is fully mixed in, add in the 1/2 cup of semisweet chocolate chips.

Spread about 2/3 of the dough in the bottom of the baking dish. Top with an even layer of the chopped nuts.

Bake for 8 minutes and place the leftover dough in the refrigerator.

After those 8 minutes, remove the crust from the oven and top with an even layer of the dark chocolate chips.

Now pour over the caramel. It should be easily pourable but if it thickened too much while cooling, return it to the stove and heat just enough to loosen it up again.

Then pour an even layer of the caramel over the chocolate chips and top with random blobs of the leftover cookie dough.

Bake for 20-25 minutes or until very lightly golden.

Allow the bars to cool at room temperature for about 30 minutes, then chill for about an hour.

To release from the pan, you may need to wedge a knife around the corners depending on how well lined your pan is. Then just lift out, sprinkle with sea salt, and slice!