Add the bacon to a wire rack over a baking sheet, add to the oven, then heat the oven to 350°F (putting the bacon in the oven while it heats up will render more fat).
Once the oven heats up, set a timer for 5 minutes.
Stir together the brown sugar and the beer. Remove the bacon from the oven, brush the top side of the bacon liberally with the mixture. Return to oven, bake for 8 minutes. Flip the bacon, then brush with the mixture. Bake for an additional 8 minutes. Remove from oven, remove the bacon and allow to cool on a sheet of parchment or wax paper (if it cools on the rack, it will stick). Once the bacon is cooled, chop the bacon, set aside.
Add the butter and both types of sugar to a stand mixer with a whisk attachment.
Beat on high until light and fluffy, this can take several minutes but it’s important to make sure it’s fully whipped.
Add the eggs, yolk and vanilla, beat until it resembles frosting. Add the beer, beat until fully incorporated.
Add the flour, baking soda, baking powder, cornstarch and salt, stir until combined.
Stir in the remaining ingredients and the chopped bacon until just combined.
Add a sheet of parchment paper to a baking sheet. Using a cookie scoop, scoop out balls of dough, placing evenly spaced on the baking sheet.
Bake for 12-15 minutes or until edges have started to brown. Remove from oven, pull the parchment off the baking sheet and onto a flat surface to cool.