Add cantaloupe, lime juice, ginger, and honey to a blender and mix until smooth. Transfer to a shallow dish and place in the freezer. Every 30-45 minutes for approximately 3-4 hours, scrape and fluff any frozen bits toward the center of the dish then return to the freezer. Once ready (there should be no more liquid, only a pile of ice crystals), transfer to a container and seal with a lid (this will keep well for 2-3 weeks).
Optionally, while you wait for the granita to freeze, prepare the lime crème anglaise: Bring milk, heavy cream, and vanilla extract to a boil, then remove from heat. Mix egg yolks with sugar and lime zest, and slowly whisk in the warm milk mixture. The texture should be similar to melted ice cream. Chill in the fridge until ready to serve, then spoon a generous amount over granita. If using, add chili flakes and fresh mint.