Use a mixer to cream together the butter, sugar, dark brown sugar, and vanilla for a few minutes until well-mixed. It is possible to overwhip the butter and sugar, so stop mixing once the mixture is homogenous. Add the baking powder, baking powder, and salt and continue mixing until incorpoarted. Scrape the sides and bottom of the bowl as necessary to ensure the mixture is well-combined and homogeneous.
Mix in the applesauce until fully incorporated. The mixture may look "split" at this point.
Add the flour and mix with a spatula/spoon by hand just until no dry flour remains.
Fold in the chopped chocolate.
Scoop dough onto a tray lined with a silicone mat or parchment paper. It should make about 12 cookies 4 tbsps each.
(Optional) Top each cookie with 2-3 pieces of extra chopped chocolate.
Cover and chill in the fridge for 24 hours.
Move the tray to the freezer and freeze the dough completely before baking. About 1 hour.
Preheat oven to 375ºF.
Arrange desired number of cookies on a baking tray lined with a silicone mat or parchment paper. Bake in the center of the oven until the outer ½-in edges of the cookies are golden brown and the centers are still pale (or desired doneness). About 17 minutes for 2 cookies + 1 minute for every 2 additional cookies. 6-8 cookies can fit on a half sheet tray.