Preheat the oven to 375 degrees F. Line 2 baking sheets with parchment or silicone baking mats.
Cut the bacon into 1/2-inch pieces. Cook in a large skillet until golden and crispy, 6 to 8 minutes. Remove to drain on paper towels, reserving the fat. Strain the fat (to remove the bacon bits) and chill in the fridge until set.
Whisk together the flour, baking soda, salt, baking powder and cayenne in a small bowl. With an electric mixer, beat the butter, chilled bacon fat, sugars and vanilla until light and fluffy.
Add the eggs 1 at a time, beating well after each egg. Slowly add the flour mixture and stir to combine. Stir in the bacon and chocolate chunks.
Drop by tablespoonfuls onto the baking sheets, leaving 3 inches between each one.
Bake until set, 8 to 12 minutes.