In a medium saucepan combine water and monkfruit sweetener. Whisk together just to get the sweetener wet
Bring to a low boil over medium heat. Reduce heat to low and continue boiling for 10 minutes.. Do not stir while it is boiling
While it is boiling place powdered milk and cocoa powder into a medium mixing bowl. Whisk them together until fully combined and no lumps. Set aside
Grease 8x8 inch baking dish on the bottom and the sides then set aside
Check on the sugar and water mixture. Once it has slowly simmered for 10 minutes. Add butter and lightly stir to dampen the butter cubes
Bring to a low boil. Remove from heat. Slowly add powdered milk/cocoa mixture and vanilla extract. Whisk it all together until fully combined and smooth
Pour mixture slowly into the prepared baking dish and spread with a spatula to smooth the top.
Let it cool at room temperature 1-3 hours or until cool and firm enough to cut into solid squares. Store leftover in an airtight container in the refrigerator