Preheat oven to 375 degrees. Line a large baking sheet with parchment paper or silicone mat. Place butter and granulated sweetener in a large mixer bowl and beat on medium 1 minute or until smooth. Add the eggs, keto syrup, and vanilla extract. Beat on medium-low 30 seconds or until fully combined.
Sift together the coconut flour, cocoa powder, salt and baking powder then add to wet ingredient in the mixer bowl. Beat on medium 30 seconds or until combined. Increase speed to medium and beat 1 minute until smooth dough forms. Scrape down the sides of the bowl as needed.
Scoop the dough 1 TBS at a time onto the prepared baking sheet. Use hands and flatten the scoops out to circles of desired size and thickness. The thinner pressed out the crispier the cookies will be once cooled. Leave room between the cookies for even baking.
Place in preheated oven at 375 degrees for 8 to 10 minutes or until darkened around the edges. Remove from the oven and cool on the pan at least 10 minutes to firm up. transfer to a cooling rack and cool until desired level of crisp. The longer the cookies sit the crispier they become up to overnight.