Mix 1 tablespoon of butter with brown sugar and gochujang until it forms a paste.

Using a hand-held or stand mixer, beat the remaining butter with sugars, egg, and vanilla until the mixture is creamy and fluffy.

In a separate bowl, whisk together flour, baking soda, salt, and cinnamon. Gradually add this to the butter mixture, stirring until combined. Refrigerate the dough for 10-15 minutes.

While the dough chills, preheat your oven to 350 degrees Fahrenheit. Line two baking sheets with parchment paper or silicone mats.

Remove the dough from the fridge. Add dollops of the gochujang caramel paste to the cookie dough. Use a stiff spatula to gently swirl the caramel into a marbling pattern in the dough, ensuring you maintain a visible color contrast.

Bake the cookies for 11-13 minutes, until they show cracks on the top and are golden around the edges. Rotate the pans halfway through for even baking.

Allow the cookies to cool on the baking sheets for about 3 minutes before transferring them to a cooling rack.

Store the cookies Keep them in an airtight container at room temperature. They'll stay good for up to three days.