Preheat the oven to 350°F. Line a cupcake pan with cupcake papers.
In a small bowl, combine the cocoa powder and boiling water, whisking until blended and smooth; set aside.
In a large mixing bowl, combine the flour, monk fruit sweetener, baking soda and salt. Add the butter and mix with an electric mixer until the mixture is crumbly.
In a separate bowl, combine the eggs, milk, cocoa mixture and vanilla. Add ⅓ of the wet mixture to the dry mixture. Beat on low speed with electric mixer until blended. Beat at medium speed for an additional 30 seconds until the mixture is smooth (scrape down sides of bowl, as needed). Repeat two more times, until all the wet mixture has been added.
Scoop the batter into the prepared cupcake pan. Fill 10 cupcakes for a fuller cupcake, or 12 for smaller cupcakes.
Bake 20 to 22 minutes or until a toothpick inserted into the center comes out clean. Remove from the pan; cool completely on a wire rack.
Notes
Sweetener Notes: We used Better Body Foods Monk Fruit Zero Calorie Sweetener for this recipe. It's a Monk Fruit Erythritol blend. Other brands are Splenda Monk Fruit and Lakanto. They are all available at Walmart.