Preheat the oven to 350°F. Line 2 baking sheets with parchment paper or silicone baking mat.
Beat together the butter and sugars until light and fluffy. Add in the egg and vanilla until fully combined.
In a small bowl, mix together the flour, cocoa, chocolate pudding mix, salt and baking soda.
Slowly mix in the dry ingredients to the wet ingredients until fully incorporated. Fold in the white chocolate chips.
Scoop the cookie dough on the prepared baking sheets, and bake for 8-10 minutes. Allow to cool on the baking sheets for around 5 minutes, then transfer to wire racks to cool completely.