Instructions for preparation and cooking:
1. Heat the oven to 180 degrees Celsius (about 350° Fahrenheit). Grease a 12-cup Bundt cake pan with 1 tbsp of butter. Cut all the biscuits into quarters and set them aside.
2. In a big microwavable bowl, put the marshmallows, half a cup of butter, the chocolate syrup and the vanilla extract. Heat them uncovered on the highest setting for 1 to 2 minutes, stirring only once, until the mixture is melted. Stir the mixture with a wire whisk, until it is nicely smooth.
3. In a medium sized bowl, mix the sugar and cocoa until they are well combined.
4. Gently place a quarter of the biscuit pieces into the hot chocolate mixture, carefully folding them to coat on each side. Repeat the procedure with another quarter of the biscuits. Remove the biscuits from the chocolate mixture with tongs, letting the excess chocolate to drip off. Then, drop one biscuit piece at a time into the sugar cocoa mixture; also pour over a spoon of the mixture over the biscuit to coat it on each side. Place the biscuits in the cake pan. Do the same with the remaining biscuits. If you have left any of the sugar cocoa mixture, sprinkle it over the biscuits.
5. Bake for 30 to 40 minutes or until the biscuits get deep golden color and are no longer doughy in their centers. Let the cake cool in the tray for 5 minutes.
Here is a very cool trick how to serve this dessert: place a heatproof serving plate upside down over the pan; carefully turn the plate with the tray over. Remove the pan and scrape the remaining chocolate mixture in the pan over the cake.
Pull apart the warm biscuits and serve them right away, since you do not want to let your friends suffer and wait any longer 🙂