Preheat the oven to 350°F (180°C). Line a rectangular baking sheet with parchement paper.
In a bowl, sift together all the dry ingredients (flour, cornstarch, cocoa powder, baking powder, baking soda, and salt) and set aside.
In another bowl using a hand mixer, cream together butter and confectioners sugar for 2 minutes until light and fluffy.
Stir in the egg, egg yolk, honey, vanilla extract, orange zest and beat for another 1 minute until everything´s well incorporated.
Slowly add in the dry ingredients using a rubber spatula and stir until you get a soft dough.
Wrap the dough up with some plastic kitchen paper and put it in the fridge for 30 minutes, for it to be easier to work with afterwards.
Once out of the fridge, place the dough on a clean surface and roll it out using a roller until about 1/4 inch thick. Cut out circles, about 2.7 inches (7cm) diameter each.
Place the cookies on the baking sheet and bake at 350°F (180°C) for 15 minutes just until they´re cooked, (it´s important they don´t turn golden).
To assemble:
To put together the alfajores, spread one cookie with enough quantity of dulce de leche and then place another cookie on top, press a little and set aside. Do this with all cookies. Let them rest a little.
Meanwhile, to make the ganache, place the chocolate on a heat resistant bowl. Pour the cream in a small pot and heat it to medium temperature for 2 minutes on the stove until it starts to boil. Quickly pour it over the chocolate and let it sit, without stiring, for 5 minutes. Once this time has passed, mix it all to until a not so thick ganache forms.
Cover the alfajores with the chocolate ganache, using a fork and spoon, and let them sit on a cooling rack until they dry completely.