Toast Sesame Seeds

1. In a dry skillet over medium-high heat, toast sesame seeds until lightly browned, 2-3 minutes. Once at desired color, transfer to a dish to stop the oils from toasting. Set aside

Make Dough

1. Melt 4 tbsp butter in a small skillet over medium heat and allow to bubble and brown until golden and fragrant, about 3 minutes
2. Pour the hot browned butter into the bowl of a stand mixer and add cocoa powder, cinnamon and espresso. Mix to incorporate ingredients, scraping down the sides of the bowl
3. Turn on low speed and stream sugar into running mixer (this helps cool it a bit so you don't melt the chilled butter added next)
4. Once sugar is fully incorporated, add sliced butter to the somewhat cooled mixture, 1 piece at a time, and increase speed to high and beat until creamed, 2-3 minutes. The color will go from almost black to a rich brown, frostng-like texture
5. Reduce speed to medium and add egg yolks. Beat until batter is nice and thick
6. In a separate bowl, with a whisk, mix the whole wheat and oat flours, baking soda, salt and sesame seeds. Add to the mixer and incorporate all ingredients on medium speed, scraping down the bowl

Portion & Chill

1. For scoop-and-bake cookies, portion onto parchment-lined baking sheet (these can also be rolled in coarse sugar for a sparkly look)
2. For cut-out cookies, divide dough roughly in half, place in zip-top freezer bags. Push flat in bags and seal
3. For slice-and-bake cookies roll into a log and wrap in plastic (for variation, roll log in coarse sugar or crushed nuts)
4. For all variations, chill dough for 30 minutes or up to 3 days (these will also freeze indefinitely; then allow dough to come to a cool room temperature before rolling out)

Bake & Serve

1. Preheat oven to 350º
2. For the cut-out cookies, cut the dough out of the zip-top bags and place on parchment paper with another layer of parchment on top
3. Roll dough to ¼” thick, remove top layer of parchment, and cut into desired shapes but do not remove shapes from the dough, cover with parchment, and chill for an additional 15-20 minutes (the dough is so tender that it will start to fall apart when transferring unless thoroughly chilled) (slice-and-bake and scoop cookies do not require this extra chilling step)
4. Remove cut-out cookies from refrigerator and transfer shapes to parchment-lined baking sheet. Bake all cookie variations (scooped, cut-out and slice-and-bake) 8-12 minutes. They can even be baked together – none of the variations spread much in the oven
5. Once done, slide cookies (parchment and all) onto a cooling rack. Allow to cool completely before removing from parchment