Cut the butter into pieces and melt in a small saucepan on the stove, or in a microwave-safe bowl in 15-second increments. Set aside for 15 minutes to cool while you gather the rest of the ingredients.
Add brown sugar and granulated sugar to the bowl of a stand mixer (or use a hand mixer). Pour in the melted and cooled butter, and beat at medium speed for 4 minutes. Scrape down sides.
Beat in the whole egg and egg yolk until completely mixed in, then add vanilla and beat another 30 seconds. Mixture will look like a silky batter.
In a mixing bowl, stir together bread flour, salt, baking soda, and cinnamon.
Add dry ingredients to wet ingredients, 1 cup at a time. Scrape down sides after each addition. Once all of the flour mixture is incorporated, stir in the chocolate chips and pecans until evenly distributed.
Scoop dough into large balls (about 3 tablespoons) and place on a parchment lined baking sheet. Arrange the dough balls closely so they all fit onto one pan. Once all of the dough is portioned, place the baking sheet in the refrigerator and chill for at least 3 hours, or overnight.
When ready to bake, preheat oven to 350°F. Line another baking sheet with parchment paper.
Arrange 6 cookie dough balls onto the baking sheet. Bake for 13-15 minutes, until golden brown. Let rest on the baking sheet for a minute or two, then transfer to a wire rack to cool.
Repeat with remaining dough, or freeze extra dough balls for up to 3 months.
Notes
A large cookie scoop will make perfectly sized cookies.
All-purpose flour can be substituted for the bread flour.
If making smaller cookies, reduce baking time to about 10 minutes.
If baking from frozen, add 2-3 minutes to baking time.