Preheat oven to 350 degrees. On the top half of a double boiler over medium heat, melt the butter and chocolate together, whisking to blend. When the chocolate and butter are fully melted, remove the chocolate from the stove. In a mixing bowl, whisk the whole eggs plus the yolks together with all of the sugar until well blended, being careful not to incorporate air. When chocolate/butter mixture has cooled, add egg and sugar mixture, add the flour by hand with a whisk, again being careful not to incorporate air. Butter and flour 4 (approximately 4-ounce) cake molds, tapping the pan to remove excess flour, and pour the chocolate batter into the pan. Place in the middle rack of the oven and bake for 8 minutes. Unmold and serve warm.
Warm the half and half and Armagnac in a saucepan over medium heat until it comes to a boil, then remove the saucepan from the stove. While the half and half is heating, whisk the sugar and egg yolks in a bowl until pale lemon in color. Add the sugar/egg yolk mixture to the half and half and return to the stove over very low heat. Stir constantly with a wooden spoon until the foam on the top disappears and the mixture is thicker and coats the back of the spoon. Remove from the stove immediately and stop the cooking by placing the saucepan in a bowl of ice, stirring the mixture to cool it. Freeze in an ice cream maker according to manufacturer's instructions.
Recipe courtesy of Rocco DiSpirito, Union Pacific, New York, NY