Preheat oven to 350 degrees. Line cupcake tins with 18 paper liners and set aside.

In a large bowl, combine flour, sugar, cocoa powder, baking soda, baking powder, and salt. Using a wire whisk, blend the dry ingredients thoroughly.

Add the oil, prepared hot cocoa, vanilla and eggs to the dry ingredients. Whisk until well incorporated and no lumps remain. Stir in the chocolate chips.

Evenly divide the batter between the lined cupcakes tins.

Bake the cupcakes for 18 to 20 minutes, or until a toothpick inserted into the center comes out clean. Allow to cool for 10 minutes; then place them on a rack to cool completely.

In a medium bowl, combine heavy cream, powdered sugar and vanilla extract. With an electric mixer on medium speed, beat until thick, creamy, and slightly stiff, being careful not to overbeat.

Pipe or mound the sweetened whipped cream onto the cooled cupcakes. Garnish with a sprinkling of mini marshmallows, mini chocolate chips and crushed peppermints. Add a mini candy cane tucked into the side of the cupcake, to make a handle for the "mug" of hot cocoa.

Serve immediately. Cover and refrigerate any leftovers. Makes 18 cupcakes.