In a microwave safe bowl make the ganache by melting 1/4 cup chocolate chips with 1/4 cup whipping cream. Whisk every 30 seconds until fully combined. Set aside to cool. Next melt the remaining 1/4 cup chocolate chips and set aside. Fill the bottom of a parfait cup with 1/4 cup of graham crumbs.
In a stand mixer with the whisk attachment whip the remaining 1/2 cup whipping cream into soft peaks. Add 3/4 tsp vanilla and whip into stiff peaks. Scrape into a bowl and set aside. With the paddle attachment beat the cream cheese until it's super smooth - no lumps people! Sift the icing sugar into the cream cheese and beat well, scraping down sides as you go. Stir in the whipped cream and the 1/4 cup melted chocolate chips until just combined. Spoon half of the chocolate cheesecake into the parfait cup and spread evenly.
Sprinkle half of the mini marshmallows over the chocolate cheesecake, pour half of the ganache over the chocolate cheesecake layer and then the second half of the graham crumbs. Spoon the second half of the cheesecake out and spread evenly before sprinkling the second half of the marshmallows. Top off with the rest of the ganache.
In the stand mixer with the whisk attachment whip the egg white with the cream of tartar and vanilla until soft peaks form. Slowly add the white sugar as the eggs are whipping until firm peaks form. Spoon onto the top of the parfait and make some pretty little peaks. With a kitchen torch, toast the meringue. Grab a couple spoons and dive in!