Place 6 silicone (or paper) muffin cups in a muffin tin. I used a 6-muffin tin but you can use a 12-muffin tin, too.
Place ½ cup of chocolate chips in a microwave safe bowl together with ⅔ of a teaspoon of coconut oil. Melt by microwaving in 15-30 second increments and stirring until completely melted and pourable.
Divide the melted chocolate between the 6 muffin cups. Using a silicone brush spread the chocolate on the bottom and sides of each to about ½ height of the muffin cups. Place the muffin tin in the freezer to set.
Make the filling: place corn flakes in a zip lock bag, close it and crush the corn flakes with a rolling pin until they resemble coarse meal. Transfer to a medium bowl.
Add pistachio cream and mix with a spoon or rubber spatula until incorporated. The mixture will be thick and sticky. Set aside.
Take the muffin tin out of the freezer and divide the filling between the 6 cups. Press and flatten gently to fill each cup.
Melt the remaining chocolate chips and coconut oil until pourable.
Pour a little bit of chocolate over each of the 6 cups and spread with silicone brush to cover completely.
Garnish with chopped pistachios, if you want.
Place in the fridge for at least 30 minutes, then gently remove from the silicone cups and enjoy!