Add butter, vanilla, and applesauce to mixing bowl, then mix on low with electric mixer.
Add FitHackr Cookie Protein, then mix on high with electric mixer until smooth and creamy.
Add FitHackr Cookie Flour, cocoa powder, and instant espresso powder, then mix with spoon until fully combined.
Set aside some of the white chocolate for topping, then add dark chocolate and remaining white chocolate into bowl and mix to evenly distribute in the dough.
Chill in refrigerator for at least 30 minutes to allow the dough to come together and the four the fully hydrate.
Line a cookie sheet with parchment paper and spray with oil.
Scoop balls of dough (about 2 tablespoons each) with a cookie scoop (or spoon) and drop onto cookie sheet. Top each cookie with a few pieces of white chocolate.
Bake at 350°F / 175°C for 5-7 minutes, remove from the oven, sprinkle sea salt flakes on top, then let the cookies rest for 3-5 minutes
Shape cookies into nice, round circles with a spoon or circular device (e.g. biscuit cutter, cup, mason jar ring, etc)
Place back into oven for another 5-7 minutes, until centers are no longer wet and you can smell the aroma coming from the oven.
Remove from oven, give cookies another, final shaping, then optionally sprinkle more sea salt flakes on top.
Let cool for ~5 minutes on cookie sheet before transferring to a wire cooling rack. Enjoy them now if you prefer hot and gooey, or let them cool completely for a dense, soft, and chewy texture.