Just look at those marshmallow pulls!
Heat the chocolate and butter in a bowl either in a microwave or over a bain marie.
Whisk together sugar, vanilla and eggs. Add the chocolatey butter mixture.
Sift in the cocoa powder, plain flour, baking soda and salt. Just bring the mixture together, being careful not to over knead.
Cover and let the mixture set in the fridge for at least an hour. Preheat the oven to 180°
Scoop out pieces of the dough (roughly 55g in size), roll them to warm them up and place on a baking sheet. Squash them to flatten out. Press chocolate into the cookies.
Bake for around 10 - 15 minutes. When they've almost set (but are still gooey with a chocolatey ooze) toast the marshmallows on a stick until they are caramelised and gooey. Stick them between two cookies and serve, rolled in the crushed Doritos.