Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9-inch round cake pan.
In a medium bowl, whisk together the flour, cocoa powder, baking soda, and baking powder. Set aside.
In a large bowl, cream together the sugar and 1/2 cup butter with an electric mixer. Beat in the eggs one at a time, then stir in the vanilla. Add the flour mixture alternately with the buttermilk; mix until just blended. Fold in the chocolate chips.
Pour the batter into the prepared pan. Bake in the preheated oven for 30 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool in the pan for 10 minutes before turning out onto a wire rack to cool completely.
To make the frosting, melt 1/2 cup semisweet chocolate chips over low heat. In a medium bowl, beat together 1/2 cup heavy cream and 1/4 cup butter until light and fluffy. Gradually beat in the confectioners' sugar and melted chocolate until smooth. Beat in the 1/2 teaspoon vanilla extract.
Spread the frosting over the cooled cake.
Interesting Facts
Death by Chocolate cake is a popular dessert in the United States.
It is believed that the cake originated in the early 1980s.
The cake is often served with a scoop of vanilla ice cream.