I have a separate post on how to caramelize white chocolate. It's very easy, and makes a huge difference in the taste. Once it's fully cooled and set, roughly chop into small pieces and set aside. Note, you do need to do this ahead of time, I recommend a day ahead.

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

In a medium bowl (you can also make this in your stand mixer), whisk the melted butter, tahini, brown sugar, and white sugar together for a couple minutes, getting it nice and glossy and emulsified.

Add the egg and vanilla and whisk for 30 seconds.

Add the flour, baking soda, salt, and cinnamon and mix until mostly incorporated but still a little floury.

Add the caramelized white chocolate chunks, and gently mix to incorporate.

Using a spoon, scoop out equal portions of dough and shape or roll into a rough ball. Place on the prepared baking sheet at least 3 inches apart (they will spread somewhat). Sprinkle with sesame seeds and flaky sea salt.

Bake until golden brown around the edges, 10 to 13 minutes. Allow the cookies to cool on the pan for 5 minutes, then transfer to a wire rack to continue cooling.