Make the caramel first, so that it has time to cool. If needed, this can be made up to 2 weeks in advance and stored in an airtight container in the fridge.

Place a medium saucepan over medium to medium-high heat. Once the pan has warmed up, pour in 1 cup of sugar gradually, adding ¼ cup at a time. Stir as needed with a rubber spatula. Wait until the sugar is mostly dissolved, then add in the next bit of sugar. As the sugar melts it will gradually deepen in color.

Stir occasionally until the sugar is fully dissolved and has become an amber color, then turn off the heat.

Slowly mix in 6 Tbsp of butter (2 Tbsp at a time), then stir in ½ cup of heavy cream, 1 tsp vanilla extract or vanilla bean paste, and ½ tsp fine salt. The mixture will be thin but will thicken as it cools. Pour into a separate container, then place in the fridge to speed up the cooling process.

Once the caramel has reached room temperature, whip it with a hand mixer or stand mixer on a medium-high speed for 1-2 minutes, until it becomes lighter in color and looks thicker. Set aside.

While the caramel cools, make the brownie batter. Preheat the oven to 325 F / 162 C and line and grease an 8x8-inch square metal pan with parchment paper. If you don't have a square pan that size, you can also use a round 8- or 9-inch metal pan. Set aside.

In a medium bowl, mix together 1 ½ cups sugar, ¾ cup flour, ⅔ cup cocoa powder, ½ cup powdered sugar, ½ cup chocolate chips, and ½ tsp salt. Set aside.

In a large bowl, whisk together 2 large eggs, ¼ cup vegetable oil, ¼ cup melted butter, 2 Tbsp water, and 1 tsp vanilla.

Pour the dry mix into the wet ingredients and stir until just combined. The mixture will be pretty thick, but that's how it's supposed to be!

Pour the batter into the prepared pan and smooth it into an even layer. Bake at 325 F / 163 C for 40-45 minutes, or until a toothpick comes out with a few moist crumbs.

Set it on a wire rack to cool fully before topping. If you want to accelerate the process, place the pan in the freezer for 30 minutes.

Once the brownies are fully cooled, scoop the room-temperature caramel on top and spread it into an even layer.

Add a sprinkle of flakey sea salt, then use a sharp, warm knife to cut into the chilled brownies. Clean the knife after each cut to get perfect slices. Leftover brownies can be kept at room temperature in an airtight container for 2 days, or in the fridge for up to a week.