Despite what you might think, Champagne Cognac is not made from Champagne, in the region of Champagne, nor from the grapes used to make Champagne. Champagne is made from Chardonnay, Pinot Noir, and Pinot Meunier grapes. Cognac is most often made from Ugni Blanc grapes. Confusing, I know.
What Champagne and Cognac do have in common is that they are both grape-growing regions in France, the former for sparkling wine, and the latter for brandy. While no sparkling wine can be labeled as Champagne other than those made in the Champagne region, in the famous brandy-making region of Cognac, there are six different growing regions, two of which have Champagne in their names: Grande Champagne and Petite Champagne. These two regions get their names due to their chalky soils, similar to the soils in the Champagne region.
If Cognac is made with at least 50 percent of its grapes coming from the Grande Champagne region, and the remaining grapes coming from the Petite Champagne region, it may be called a Fine Champagne Cognac. If 100 percent of the grapes come from the Champagne region, it may be called Grande Champagne Cognac or 1er Cru, as this is the most celebrated of the six Cognac growing regions.