Prepare a baking sheet with parchment paper and set aside.
In a mixing bowl add the softened butter, white and brown sugars. Use a mixer to blend until combined.
Add the eggs, corn syrup and vanilla extract. Blend again until combined.
Add in the rest of the dry ingredients at once. Blend together with the mixer until combined, scraping down the side of the bowl if necessary.
Use a spoon or scoop to make 2 tablespoon size balls of the chocolate cookie dough and roll into a ball. Place on the baking sheet.
Repeat, fitting 8 cookies on a pan at a time with about 2 inches of space in between.
Press down on each dough ball to create a disc shape.
Bake in the oven for 10 minutes or until you start to notice the edges of the cookie crack.
While the cookies are baking make the ganache.
Add the chocolate chips to a heat safe bowl. In a saucepan heat the heavy cream over medium heat until steaming but not boiling. Pour the heavy cream over the chocolate chips and let sit for 5 minutes.
Stir together until a smooth ganache is created. Set aside.
Once the cookies are out of the oven, let them cool.
Make the marshmallow frosting using the double boiler method. Place water in a pot on the stove and simmer. Put a heat proof bowl on top of the pot.
Add the egg whites and sugar to the bowl. Continuously whisk over the heat until the sugar has dissolved in the egg whites. This will take about 5 minutes.
Remove the egg white mixture from the heat. Use a hand mixer or stand mixer to whisk the mixture together until white, fluffy and peaks form.
Add the marshmallow fluff and vanilla extract. Mix on high again until stiff peaks form.
Place into a piping bag fitted with a round metal tip.
Place a large swirl of the marshmallow frosting onto each chocolate cookie.
Then place a tablespoon full of ganache on each cookie, spreading evenly to coat most of the marshmallow layer.
Lastly, melt the white chocolate chips in the microwave for 30 second intervals, stirring in between until completely melted.
Place in a piping bag and snip the end. Create the famous Hostess cupcake swirls on each chocolate cookie, topping the ganache.
Keyword chocolate, hostess cupcakes, molded cookies