Combine Liquids: In a medium-sized saucepan, pour in the water and maple syrup. Place over high heat.
Bring to Boil: Whisk continuously and bring the mixture to a boil.
Reduce Heat and Simmer: Once boiling, reduce the heat to medium-low and maintain a gentle simmer.
Add Cocoa Powder: Vigorously whisk in the cocoa powder until fully integrated.
Monitor and Stir: Allow the mixture to reach a rapid simmer over medium heat. Cook for 8-10 minutes, whisking every 30 seconds to prevent burning.
Check Consistency: To test, coat the back of a spatula with the syrup and draw a line with your finger. If the line holds, the syrup is ready.
Cool and Store: Remove from the heat and allow the syrup to cool in the pot for about 5-10 minutes, then pour into a heat-proof glass jar and seal. Enjoy the syrup warm or cold over ice cream, in milkshakes, or to make chocolate milk. Or refrigerate the syrup for at least 2 hours or overnight to thicken it further. It can be stored in the refrigerator for up to 2 weeks.
Notes
Store the chocolate syrup in an airtight glass jar in the refrigerator, where it will thicken and stay fresh for up to two weeks.