In a medium bowl, whisk together 1½ cups (188 grams) flour, cinnamon, 1 teaspoon (3 grams) salt, and ½ teaspoon (2.5 grams) baking powder. Set aside.

In the work bowl of a food processor, place pecan pieces and 2 tablespoons flour mixture; pulse until pecans are finely ground. (See PRO TIPS.) Add pecan mixture to remaining flour mixture, whisking to combine.

In the bowl of a stand mixer fitted with the paddle attachment, beat ½ cup (113 grams) butter and brown sugar at medium speed until creamy, 2 to 3 minutes, stopping to scrape sides of bowl. Add 1 egg (50 grams) and 1 teaspoon (4 grams) vanilla, beating until combined. With mixer on low speed, gradually add flour-pecan mixture to butter mixture, beating until combined. Turn out dough onto a lightly floured surface, and shape into a disk. Wrap in plastic wrap, and refrigerate for at least 1 hour.

Clean bowl of stand mixer and paddle attachment. Using the paddle attachment, beat granulated sugar and remaining ½ cup (113 grams) butter at medium speed until creamy, 2 to 3 minutes, stopping to scrape sides of bowl. Add 1 egg (50 grams) and remaining 1½ teaspoons (6 grams) vanilla, beating until combined.

In a medium bowl, whisk together remaining 1⅔ cups (208 grams) flour, remaining ½ teaspoon (1.5 grams) salt, and remaining ½ teaspoon (2.5 grams) baking powder. With mixer on low speed, gradually add flour mixture to butter mixture, beating until combined. Turn out dough onto a lightly floured surface, and shape into a disk. Wrap in plastic wrap, and refrigerate for at least 1 hour.

Let doughs stand at room temperature until slightly softened, about 5 minutes. On a lightly floured sheet of parchment paper, roll vanilla dough into a 14×10-inch rectangle (⅛ inch thick). Transfer dough on parchment to a baking sheet. Refrigerate for 15 minutes. Repeat procedure with pecan dough.

Transfer vanilla dough on parchment to a flat surface. Carefully invert pecan dough on top of vanilla dough. Between sheets of parchment, gently roll over doughs a few times to press together. Peel away top sheet of parchment. Starting at one long side, roll dough into a log, using bottom sheet of parchment to help lift and roll. (If dough cracks, stop rolling, and let stand for a few minutes until pliable.) Be sure to roll doughs together as tightly as possible to avoid gaps. Trim any pecan dough if uneven after rolling. Tightly wrap in parchment paper, twisting ends of parchment to seal. Transfer to a baking sheet, seam side down. Refrigerate for at least 2 hours, or freeze until ready to use.

Preheat oven to 325°F (170°C). Line 2 baking sheets with parchment paper.

In a small bowl, whisk remaining 1 egg (50 grams). In another small bowl, stir together chopped pecans and turbinado sugar. Pour onto a piece of parchment paper. Brush log with egg wash, and roll in pecan sugar. Roll back and forth a few times so sugar sticks to log. Using a sharp knife, cut log into ½-inch-thick slices. Place about 1 inch apart on prepared pans.

Bake until edges are just beginning to turn golden, 12 to 14 minutes, rotating pans halfway through baking. Let cool completely on pans. Store in airtight containers for up to 2 weeks.