Preheat the oven to 350°F and line a baking sheet with parchment paper.
Stir together almond flour, cocoa powder, powdered monk fruit sweetener, coconut flour, baking powder, and salt in a bowl.
Beat the softened butter, egg, and vanilla extract until smooth. Add the dry mixture and fold until a thick dough forms, then mix in the sugar-free dark chocolate chips.
Melt 2 tbsp butter in a small skillet over medium-low heat. Add the coconut flakes and pistachios, stirring for 3 to 4 minutes until fragrant and lightly toasted.
Remove the skillet from the heat and stir in powdered monk fruit sweetener, tahini, vanilla extract, and salt until the mixture turns glossy and clumpy.
Scoop the cookie dough into 12 mounds, flatten slightly, and press a spoonful of pistachio crunch into the center of each cookie.
Bake for 10 to 12 minutes, until the edges are set but the centers still look soft. Cool on the baking sheet for 15 minutes before serving.