In a medium bowl, whisk together gluten-free flour, xanthan gum (unless flour blend already has xanthan or guar gum), baking soda and salt. Set aside.

In the bowl of your stand mixer, place the cream cheese, then pour melted butter over it. Add brown sugar and sugar and mix on medium speed for 2 minutes. (I use the paddle attachment on my mixer.)

Add vanilla extract and egg yolks (one at a time) mixing on low-medium speed until well mixed.

Add the flour mixture that you set aside earlier, beating on low until just combined.

Add both sizes of chocolate chips and mix on low or by hand, just until mixed thoroughly.

Spread into lightly greased 9x13 metal pan. Bake in preheated 350˚ oven for 25 minutes. Remove from oven, sprinkle with additional 1/4 cup of chocolate chips and return to oven for 2-3 more minutes.

Remove from oven and place pan on cooling rack. Let cool before cutting. (Note, to save your pan from getting scratched up, I like to use a plastic knife to cut the bars.)

You can cut these whatever size you'd like of course, anywhere from 12 big bars to 24 smaller ones. Enjoy!