Using a double boiler pan, add 1 cup of chocolate chips over medium-high heat and 3 tbsp cooking oil. Bring to a boil, stirring chocolate chips regularly. Stir until chocolate is fully melted.
Spread out parchment paper on a flat surface.Dip mango pieces in the chocolate using a fork or tongs. Mango pieces can be fully dipped or partially dipped, depending on desired appearance.
Lay pieces on parchment paper to dry. Immediately sprinkle with any add-in while the chocolate is still moist.
Place in the freezer to fully cool for 10-20 minutes.