You can bake New York black and white cookies by mixing the main ingredients, which include chocolate chips, sugar and butter. You also have to add flour and eggs.
Preheat the oven to 375 degrees Fahrenheit and butter baking sheets. Cream 1/2 cup of sugar and butter until smooth. Add the 2 eggs, one at a time, and then mix in 1/2 teaspoon of baking powder, 1/4 teaspoon of salt and 1 1/4 cups of flour. Line your baking sheets with parchment paper, using a dab of butter in each corner to maintain the paper in place. Drop tablespoons of the mixture a couple of inches apart onto the baking sheets, and bake for approximately 20 minutes until the edges begin to brown.
With a spatula, transfer the cookies to a rack and let them cool completely. Put 4 cups of confectioner’s sugar in a bowl and mix in hot water by the spoonful until the mixture is consistent and thick. Place half of the frosting on the top of the pot, over simmering water. Add in 1 ounce of bittersweet chocolate.
Boil the mixture, stirring constantly, until the chocolate melts. Remove the pot from heat. Use a brush or the edge of the spatula to coat half of the cookies with chocolate frosting and the other half with white frosting. Leave on waxed paper until the frosting hardens. You can serve the cookies right away, or you can keep them in airtight containers at room temperature for up to three days.