In a medium saucepan, before turning on the stove, mix together 1/2 cup brown sugar, 1/4 cup unsweetened cocoa powder, and 2 tablespoons cornstarch.
Slowly add in ½ cups 2% milk and whisk until the mixture is smooth.
Place the pan over medium heat, and stir continuously while adding in the remaining 2 ½ cups 2% milk.
Once the mixture has started to thicken (about 7-10 min), turn off the stove and remove the pan from the heat while still stirring. Let the chocolate mixture cool for a few minutes.
Transfer the chocolate mixture into a spouted measuring cup. (This will make pouring it easier.) Then fill the popsicle molds almost to the top. Insert the popsicle sticks or mold tops and freeze for 6 hours or overnight.
When your ready to eat, take out a fudgesicle and enjoy! If you have any trouble getting the pops to release from the mold, run the bottom of the mold under warm water just until the pop releases.