In the bowl of your stand mixer, fitted with the paddle attachment, mix the butter on medium-high speed until light and creamy. Add cream cheese to the butter and mix until smooth and creamy. Scrape down sides of the bowl as needed to ensure butter and cream cheese are incorporated. Add both sugars and mix on medium-high until mixture is light and fluffy. Add egg and beat into mixture until fully incorporated. Add the vanilla extract and rum extract. On low speed, slowly add the flour, cornstarch, baking soda, salt and nutmeg. Mix until just incorporated. Add the Baileys Chips and chocolate chips to the dough on low speed until just combined.

Remove bowl from mixer and use a rubber scraper to ensure all ingredients are fully incorporated. Place dough in an airtight container and refrigerate overnight or freeze for up to 1 month.

After dough has chilled, preheat oven to 350-degrees. Line two cookie sheets with a Silpat or parchment paper. Use a standard-sized cookie scoop to scoop dough balls onto prepared cookie sheets. Bake cookies in 350-degree oven for 9-11 minutes, or until the edges are lightly browned. Or bake longer if you do not prefer super soft cookies.

Let baked cookies set on cookie sheet for 10-15 minutes, then transfer to a wire rack to finish cooling.