Whisk together water, sugar and cocoa powder in a small saucepan over medium heat. Be patient as it will take a little while for the cocoa powder to incorporate into the mixture.
1/2 cup water, 1 cup sugar, 2 Tablespoons cocoa powder
Bring to a full boil and continue to stir for 1 minute. Remove from heat and add peppermint extract.
1/4 teaspoon peppermint extract
After syrup has cooled, store in the refrigerator for up to 4 weeks. The syrup will thicken as it cools.
Video
Notes
Substitute Tips - You can substitute 1 cup of sugar for 1/2 cup sugar plus 1/2 cup monk fruit sweetener in this syrup. Bring the mixture to a light simmer and remove from the heat. If simmered or boiled too long the syrup will solidify too much once refrigerated.