Step 1Place the sugar and orange peel in a food processor bowl. Process for a minute or so, scraping down with a rubber spatula as necessary, until peel and sugar are finely blended.
Step 2Cut the butter into pieces and process until smooth and almost fluffy. By drops, cream in one-half cup of the orange juice, then the orange liqueur, plus more drops of juice if needed. Mixture should be creamy.
Step 3Cover and refrigerate if making ahead.
Step 1Place the milk, cold water, egg yolks, sugar, orange liqueur, flour and melted butter in the blender jar. Cover and blend at high speed for 1 minute. If bits of flour adhere to sides of jar, scrap down with a rubber spatula and blend 3 seconds more. Cover and refrigerate for at least 2 hours or overnight.
Step 2Rub the crepe pan or skillet with the bacon or rind or brush it lightly with oil. Set over moderately high heat until the pan is just beginning to smoke. Immediately remove pan from the heat and holding handle with one hand, pour a scant one-fourth cup of batter into the middle of the pan with the other hand. Quickly tilt the pan in all directions to run the batter all over the bottom of the pan in a thin film, about 4 to 5 inches in diameter. Pour any batter that doesn't stick to the pan back into the bowl. The process should only take 2 to 3 seconds.
Step 3Return the pan to heat for 60 to 80 seconds. Then jerk and toss the pan sharply back and forth to loosen the crepe. Lift its edges with a spatula and if the underside is a nice light brown, the crepe is ready for turning.
Step 4Turn the crepe by using two spatulas or with your fingers.
Step 5Brown lightly for about one-half minute on the other side. This second side will be a spotty brown and is always kept as the underneath aspect of the crepe.
Step 6As they are done, slide the crepes onto a rack and let cool several minutes before stacking on a plate.
Step 1Place the orange butter in a heavy large skillet and heat until it is bubbling. Dip both sides of the crepe in the butter. With its best-looking side out, fold it in half and in half again, to form a wedge. Place it at the edge of the skillet. Rapidly continue with the rest of the crepes.
Step 2Sprinkle the crepes with the sugar. Pour the orange liqueur and Cognac over the crepes. Ignite with a lighted match. Shake the skillet gently back and forth while spooning the flaming liqueur over the crepes until the fire dies down. Serve.