Start by cooking the bacon in a skillet over medium heat. You want crispy bacon that’s easy to chop up, so cook until it’s crispy and not limp at all. Cook the bacon in batches and set aside on a paper towel lined plate until cool enough to handle. Once you’re finished cooking the bacon, strain about a ¼ cup worth of the bacon grease into a heatproof bowl and place in the refrigerator until cool, at least 5-10 minutes.

Place the flour, baking soda, baking powder, salt, and cornstarch in a mixing bowl and whisk until fully combined. Set aside.

Microwave the butter until melted, starting with 30 seconds, and working in 20 second intervals until just melted (if it feels too hot, set in the fridge for a few minutes to cool). In another mixing bowl, add the melted butter, bacon grease, white sugar, brown sugar, bourbon, and vanilla and stir to combine until the sugars look mostly incorporated. Add the egg, then the egg yolk, stirring between each addition. Let the mixture rest for a few minutes. This gives the sugars time to dissolve more and flavors to build.

While the wet mixture rests, coarsely chop the bacon into roughly ¼” -½” pieces. Add the dry mixture to the wet mixture, about ⅓ at a time, and mixing until combined each time. Now fold in the chocolate chips and the crumbled bacon, reserving a little of each for topping the cookies if you wish. Refrigerate the cookie dough for at least 1 hour.

Preheat your oven to 375°F / 190°C and remove the cookie dough from the refrigerator.