Preheat oven at 350-degrees. Line a 13x9 pan with foil and apply nonstick spray.
In a big bowl, beat together eggs, butter, and vanilla. In another bowl, combine the brownie dry ingredients and gradually add them to the egg mix. Fold in the chocolate chips. Set aside 1 cup of the brownie batter for the topping. Scoop the rest into the prepared pan and use an uneven spatula to even it out.
In another bowl, beat together the cream cheese blocks, cookie butter, and sugar. Once that is blended, add the egg and milk. Use an uneven spatula to spread the mixture in a thin layer across the top of the brownie batter in the pan. Dollop the reserved brownie batter on top. Use the tip of the uneven spatula or a butter knife to create swirls.
Bake pan for 35 to 40 minutes, until the very middle passes the toothpick test. Cool on a wire rack for an hour, then place in fridge to completely chill. Use the foil to lift the contents onto a cutting board. Slice up and store in a sealed container in the fridge. Keeps for at least 3 days.