Preheat the oven to 375 degrees and line a 12-well muffin pan with liners or cooking spray. Set aside.
Using a stand mixer (ideally) or a bowl and hand mixer, combine softened butter and sugar, scraping down the sides of the bowl as you go. Add the egg, yogurt, and vanilla, continuing to mix.
Next, add the flours, baking powder, and salt. Mix to combine. Depending on your batter’s consistency, add milk as needed. Note that you may just need a splash or two. You want a thick, batter-like consistency at the end.
Once consistency is achieved, add in about 3/4 of your chocolate chips (reserving some for topping).
Transfer the mixture into wells, then addhocolate chips to the tops of the batter. Bake the puffins at 375 degrees for approximately the remaining c 15 minutes.
Once a toothpick comes out clean and they are cooked through and slightly golden they are done. Once done, remove from oven and allow to cool. Then serve or pack up for later. Serve with a bit of butter and/or syrup if desired.