Preheat the Oven: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
Mix Wet Ingredients: In a large bowl, combine the natural peanut butter, unsweetened applesauce, egg, and vanilla extract. Mix until smooth.
Add Dry Ingredients: Add the almond flour, vanilla protein powder, erythritol or monk fruit sweetener, baking soda, and salt to the wet ingredients. Stir until well combined. The dough should be thick and slightly sticky.
Fold in Chocolate Chips: Gently fold in the sugar-free dark chocolate chips until evenly distributed throughout the dough.
Shape the Cookies: Using a cookie scoop or spoon, drop dough onto the prepared baking sheet, spacing them about 2 inches apart. Flatten each cookie slightly with the back of the spoon.
Bake: Bake for 10-12 minutes, or until the edges are lightly golden. The cookies may appear slightly underbaked, but they will firm up as they cool.
Cool and Enjoy: Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. Enjoy your high-protein peanut butter chocolate chip Crumbl cookies with no added sugar!