In the bowl of a stand mixer fitted with a paddle attachment, or a handheld mixer, cream together butter, brown sugar, and white sugar for 5 minutes on medium speed until light and fluffy.
Once five minutes is over, add in egg and vanilla and mix until combined.
In a separate bowl, mix flour, baking soda, and salt, and mix until combined. Add these dry ingredients to the butter mixture on low speed, and mix until just combined.
Using a wooden spoon or spatula, mix in chocolate chips or chunks until just combined. Place bowl of dough in fridge for at least 30 minutes to chill. Prepare Oreo truffle filling while chilling.
For the Oreo truffles:
Crush the Oreo cookies into a fine powder, using a blender or food processor, spice grinder, or just by hand by placing cookies in a large ziploc bag and bashing with a rolling pin.
Combine the cream cheese with the Oreo powder, mixing well until the mixture combines smoothly and evenly. Roll into 18 equal sized small balls, about the size of a walnut (around 18 g each). Place on parchment paper lined baking sheet and freeze for at least 30 minutes or until firm.
To assemble and bake:
Heat oven to 180 C (350F). Take the Oreo truffles out of the freezer, and scoop out a generous 2 tablespoon size piece of cookie dough, or enough to wrap completely around the Oreo truffle. Flatten the dough out onto the palm of your hand (kind of like a palm sized pizza dough) to make it thinner and easier to wrap around the truffle. Seal completely around the Oreo truffle, roll a little to make an evenly shaped dough ball and place on parchment paper lined baking sheet. Continue with the rest of the cookie dough and Oreo truffles, placing at least 2 inches apart on the baking sheet.
Bake for around 12 minutes or until golden brown on the edges but still soft in the center. Cool until cookies firm up, then enjoy!