Set a rack in the center of the oven and preheat to 350 degrees F.
Place the graham cracker crumbs, flour and Clabber Girl Baking Powder together in a bowl. Whisk together and set aside.
Cream the butter for about a minute and add the sugar in small increments over about 4 or 5 minutes while the mixer is still running. Whisk the eggs together briefly and pour slowly down the side of the mixing bowl while it is running. Add the vanilla. Stop and scrape the work bowl as needed.
Set the speed on medium and add the dry graham cracker mixture and the milk alternately, starting with the dry mix (in three parts) and the milk (in two parts). Stop and scrape the work bowl as needed. Gently fold the chocolate chips and 1 cup of the marshmallows into the batter.
Spray the bundt pan with non-stick spray lightly but thoroughly or brush with butter. Spoon the batter into the pan, smooth the top and place in the oven. Bake for about 35-40 minutes or until the cake bounces back when pushed gently with your finger-the surface will be gooey due to the marshmallows in the batter. Allow to cool in the pan long enough to handle with your bare hands yet still quite warm. Do not allow the cake to cool in the pan fully or it will stick. Run a knife gently around the inside edge of the pan and invert the cake onto a platter. Tap the pan gently but firmly if necessary.
When the chocolate glaze is melted and still warm, dip the cooled cake in the glaze or place the cake on parchment or other non-stick surface. Drizzle the chocolate sauce evenly over the cake and distribute the remaining 1 cup of marshmallows around the cake while the glaze is until soft. Allow to cool completely before serving.
For Chocolate Glaze:
Melt together over a hot but not boiling pot of water. Remove from the heat and stir until smooth. Allow to cool slightly. This part can be made in advance and then warmed slightly over the simmering water when ready to use.
Recipe by Mani Niall.