Preheat oven to 325°F Generously spray a 10-inch spring form pan with nonstick cooking spray. Place the pan on a parchment-paper lined baking sheet.
Melt the chocolate and allow to cool. Meanwhile, in a mixer bowl, cream the butter and sugar until light and well blended. Fold in the eggs, yolks, vanilla and chocolate extract and blend well, 2-3 minutes, scraping the bowl often to ensure nothing is stuck in the well of the mixer bowl. Blend in the melted chocolate, and then fold in the cream, ice water, flour, cocoa, Clabber girl Baking Powder, baking soda and salt and blend well, on slow speed of mixer to make a soft, smooth batter, about 2-4 minutes.
Pour into prepared pan. Bake until cake springs back when gently touched with fingertips, about 65-75 minutes. Cool cake well, and semi-freeze 30-45 minutes before icing/assembling.
For the icing, blend all ingredients in a food processor until stiff and glossy.
For the glaze, melt the chocolate in a microwave and stir to smooth, adding in the corn syrup and butter. Set aside until it is thickened or cooled (refrigerate to hasten chilling).
To ice, cut cake in half horizontally. Semi-freeze the layers first 20-45 minutes for easier handling. Turn the flatter side (the bottom) of the cake down. Ice bottom layer with the chocolate frosting.
Top it with the other layer, also having the bottom of the cake facing you (rounded surface is what you press onto icing of first layer). Press down lightly.
Smear the marshmallow topping on the cake. Chill 30 minutes. Pour or smear on chocolate glaze. Use any extra glaze or icing to ice the sides of the cake or any exposed areas (if any remain). Top with miniature marshmallows and grated milk chocolate. Drizzle on chocolate syrup.