Place molding chocolate in saucepan- heat on low until melted. Stirring frequently.
Add sugar, cornstarch, cocoa powder & milk to melted chocolate - heat over medium - stirring to combine.
Continue cooking until mixture thickens- about 10 minutes.
Remove from heat - add butter & vanilla - stir to combine.
Transfer to pop molds, insert sticks - freeze overnight.
The next day melt dipping chocolate in microwave in 30 second increments until melted & smooth
Remove pops from mold & quickly dip in melted chocolate & place on parchment lined baking sheet.
Melt white chocolate to package directions & drizzle over pops to decorate
Place pops back in freezer to set about 15 minutes
Transfer to airtight container for storage or serve immediately