1 pound bacon
2 1/2 cups flour, unbleached
1/2 teaspoon baking soda
1/2 teaspoon baking powder
1 teaspoon salt
8 tablespoons butter, softened
1 cup brown sugar, packed
1 cup sugar
1 cup peanut butter, smooth (not natural)
2 large eggs
1 tablespoon vanilla extract
1 1/2 cups salted peanuts, finely ground Turbinado sugar
Preheat the oven to 375 F. Arrange the bacon on jelly roll pans and bake for about 20-30 minutes, dipping each piece halfway through cooking. When all the fat has been rendered and the bacon is very crispy, drain the strips on paper towels. Reduce the oven temperature to 350 F. Pour the rendered grease into a metal bowl and chill it in the refrigerator (or freezer) until cool and solidified. Stir the grease occasionally to speed the cooling process.
Combine the flour, baking soda, baking powder and salt in a mixing bowl and stir until well combined. Chop the bacon or crumble it by hand into small pieces, about 1/4-inch squares.
Using an electric stand mixer beat the butter until creamy. Mix in 8 tablespoons of the cool bacon fat. Add the sugars and beat until creamy, about 3 or 4 minutes. Scrape down the sides of the bowl with a rubber spatula. Beat in the peanut butter until thoroughly combined. Add the eggs, one at a time and then the vanilla. Scrape down the sides of the bowl again. On low speed, mix in the dry ingredients. Stir in the ground peanuts and bacon until mixed.
Form the dough into golf ball-sized rounds and place them on a sheet pan, spaced about two inches apart. Dip a fork in water and press the tines into the surface of each piece of dough two times, to slightly flatten the cookie and to form a crisscross pattern. Sprinkle the cookies with a generous amount of turbinado sugar.
Bake the cookies, two sheet pans at a time, for 10-12 minutes, rotating the pans midway through baking. The outer edges of the cookies should only just begin to turn golden while the center of the cookie will still look a bit pale. Let the cookies cool for 2-3 minutes on the sheet pan before transferring them to a wire rack to cool completely.