Preheat oven to 350℉ and prepare your mini muffin pan with cooking spray or paper liners.
Melt the chocolate chips, butter, and peanut butter in a microwave-safe bowl in 30-second increments, stirring in between each, until it is completely melted. Set aside to cool for a few minutes.
Whisk the flour and baking powder in a large bowl.
Add the unsweetened applesauce and vanilla extract to the melted chocolate mixture and stir to combine.
Add the wet ingredients to the dry ingredients and stir just until the ingredients are combined, taking care not to overmix.
Using an ice cream scoop or large soup spoon, scoop the batter into the prepared mini muffin pan, filling each cup about ¾ full.
Bake for 15-20 minutes or until a toothpick comes out clean, or with just a few moist crumbs on it.
Allow to cool for about 10 minutes before removing them from the pan.