Preheat your oven to 350°F and line two baking sheets with parchment paper. Chop the dark chocolate into chunks and chop the toasted pecans into bite-sized pieces. Having everything ready before you start mixing will keep the process smooth and prevent the dough from overworking while you gather ingredients.

Melt the 3/4 cup + 1 tablespoon butter in a small saucepan over low heat, then let it cool for 5 minutes—this slight cooling prevents the egg from cooking when you add it later. Pour the cooled butter into a medium bowl and add the packed brown sugar and granulated sugar. Mix vigorously with a wooden spoon for about 2 minutes until the mixture becomes light and slightly fluffy. I find that creaming the butter and sugar thoroughly helps develop a slightly tender crumb in these cookies, which works perfectly with the bourbon and chocolate.

Add the room-temperature egg to the butter-sugar mixture and beat well for about 30 seconds until fully incorporated. Pour in the bourbon and vanilla extract, stirring until everything is smooth and combined. The room-temperature egg ensures it blends seamlessly without any lumps.

In a separate bowl, whisk together the all-purpose flour, cornstarch, baking soda, baking powder, sea salt, and ground cinnamon. This whisking combines the leavening agents evenly throughout the flour, which helps the cookies rise and crack slightly on top as they bake. Add the dry ingredient mixture to the wet ingredients and stir with a wooden spoon just until no streaks of flour remain—don't overmix, as this keeps the cookies tender.

Gently fold the chopped pecans and dark chocolate chunks into the dough using a rubber spatula or wooden spoon until evenly distributed. If the dough feels very soft and sticky, cover the bowl and refrigerate for 10 minutes to firm it up slightly—this makes scooping easier. I prefer to chill when needed rather than always, as it keeps the dough tender and prevents overdevelopment of gluten.

Using a cookie scoop or tablespoon measure, portion the dough into approximately 3-tablespoon balls and place them on the prepared baking sheets about 2 inches apart to allow for spreading. Bake for 12 minutes, until the tops appear cracked and set but the centers still feel slightly soft when gently pressed—they'll continue to cook on the hot pan as they cool. The cookies should look just barely underdone when you pull them from the oven for the best chewy-tender texture.

Allow the cookies to rest on the baking sheet for 2-3 minutes to set slightly, then transfer them to a wire rack to cool completely. Sprinkle a light pinch of fleur de sel or flake sea salt on each warm cookie if desired—this enhances the chocolate and bourbon flavors beautifully. Store in an airtight container at room temperature for up to 4 days.