Preheat oven to 325F (163C). Spread the pecans on a cookie sheet and toast for about 8 minutes or until fragrant. Allow to cool, then chop into small pieces.
In the bowl of a stand mixer, add the butter, cane sugar, sea salt and vanilla bean extract. Mix on medium for about 2 minutes or until smooth (not fluffy), stopping to scrape bowl at least once. Add the bourbon and mix again on medium for about 30 seconds, or until incorporated. Scrape down bowl. Add the cocoa nibs and pecans and mix on low until just incorporated. Scrape down bowl. Add the flour all at once, pulse to start, then mix on medium until the dough forms somewhat of a ball on the paddle and has pulled away from sides of the bowl.
On a floured work surface, dump out dough and divide in half. Shape each clump into a log, 2" (5cm) thick, gently rolling and adding flour as needed so it wont stick to you or the work surface. You'll want to make sure a hollow doesn't develop in the center of the log as this will create a hole in the middle of the cookie. It this occurs, rest the dough for about 10 minutes, then use your rolling pin to beat and condition the dough, then reroll pinching where needed to avoid the dreaded hollow log! Once the log is shaped, wrap each log in plastic wrap. Carefully place in refrigerator on a flat surface for at least two hours or up to two days.
At this point the dough can be frozen for up to two months. Be sure to double wrap the logs if freezing.
Remove the log(s) from the refrigerator, unwrap the log. Using a pastry brush, brush a thin layer of egg white all over the surface of the dough. Sprinkle the log with turbinado or raw sugar, rolling it as needed to cover the surface areas.
Line two sheet pans with parchment paper. Using a serrated knife, cut the cookies 1/4" (6mm) thick, without sawing but rather with a firm cut down. Place on sheet pan with at least 1" (2 1/2 cm) between cookies. Place back in the refrigerator for at least 20 minutes (do not skip this step or the cookies will spread). Preheat oven to 325F (160C).
Bake cookies for 23-26 minutes or until golden, starting to check on them at about 20 minutes due to oven variations. They'll be darker on the bottom than the top when done. Remove from oven and using an offset spatula, carefully transfer cookies to a cooling rack to cool completely. They'll crisp up as they cool.
Store in a covered container at room temperature for up to two weeks.