Reserve 1 cup of the whipping cream in a large bowl.
Combine the remaining whipping cream, milk, sugar, and cocoa powder in a medium pot. Cook over medium-high heat, whisking often, until mixture comes to a simmer.
Take the pot off the heat and pour into the reserved whipping cream. Stir in the vanilla, peppermint, and salt.
Chill this mixture completely for at least 6 hours or overnight.
Set the Vida™ by PADERNO Digital Stainless Steel Ice Cream Maker to the gelato setting and press start. Pour the chilled mixture into the freezer bowl. Churn for 35 minutes or until softly frozen and fluffy.
About 10 minutes before the gelato has finished churning, place the chopped chocolate and coconut oil in a medium metal or glass bowl and set the bowl over a pot of gently simmering water. Stir the chocolate until melted.
About 3–5 minutes before the gelato has finished churning, slowly pour in about two-thirds of the melted chocolate mixture in a very thin stream. Turn off the machine and scrape the gelato into a freezer container.
Drizzle the remaining melted chocolate mixture over top. Serve immediately or cover and freeze for up to 4 weeks.