Mix together 2 egg yolks with 1 teaspoon of cold water.
Mix together shortening, granulated sugar, egg yolks, baking soda, flour, cocoa powder and vanilla.
Press the dough into the greased 9×13 inch pan.
Sprinkle with chocolate mint baking chips.
Beat egg whites until soft peaks form.
Add the granulated sugar and beat until stiff peaks form.
Carefully spread the meringue over the chocolate mint chip layer without allowing it to touch the sides of the pan. To make this step easier, I spooned the meringue into the pan in several dollops and then spread each of them out.