Elegant chocolate-cream Yule log warms holiday tables in France

''The ancient custom of burning a Yule log at Christmas is preserved on French tables in the Buche de Noel, a cake made in the shape of a log, filled, and covered with chocolate cream icing,'' says Marie J. McGrath, a veteran professor of home economics at the State University of New York College.

Living on the shores of Lake Champlain, Mrs. McGrath should know something of the Christmas customs of the French. The cultures of northern New York State and French Canada meet in the streets, the homes, and the eating places in her town of Plattsburgh, New York, which is not far from the border of Quebec.

Marie McGrath has a French background, and at Christmas time especially she uses recipes that have been in her family for as long as four generations.

Two favorites are the Buche de Noel (Yule Log) and tourtiere, the traditional meat pie served in French homes at midnight supper after church on Christmas Eve , a time called Reveillon.

Just about every country that celebrates Christmas has special cakes, cookies , and desserts, Mrs. McGrath points out.

''The pleasure of making these holiday treats is even greater than the pleasure of eating them. People make good things to give away in the hope it will make someone else's Christmas a merrier one,'' she says.

''In Provence, 13 sweets are the required dessert for the Christmas Eve feast , and the Yule log is the most elegant among them.''

Mrs. McGrath says making a Yule log cake is time consuming ''but worth the effort.'' The following recipe, she adds, ''is not difficult. My college students have used it for many years.'' Buche de Noel (Yule Log) 3 eggs 1 cup granulated sugar 1/3 cup water 1 teaspoon vanilla 1 cup cake flour 1 teaspoon baking powder 1/4 teaspoon salt Syrup, recipe below Chocolate Cream, recipe below

Heat oven to 375 degrees F. Line 15 1/2-by-10 1/2-by-1-inch jellyroll pan with aluminum foil. Do not vary size of pan. Grease foil.

In small mixer bowl, beat eggs at high speed five minutes or until thick and lemon colored. Pour eggs into large mixer bowl and gradually beat in sugar.

On low speed, blend in water and vanilla. Gradually add flour, baking powder, and salt, beating just until batter is smooth. Pour into prepared pan, spreading batter into corners. Bake 12 minutes or until wooden pick comes out clean.

Loosen from edges, invert onto towel that has been sprinkled with confectioners' sugar. Remove foil, then roll cake and towel into log shape. Cool on wire rack a short time.

Unroll, brush with syrup and spread with Chocolate Cream. Roll as a jelly roll. Wrap in waxed paper and chill thoroughly until frosting becomes firm. Remove waxed paper and cut off ends of cake diagonally for use as a ''stump.''

Brush outside of cake and branches with syrup. Set branches aside. Frost cake with Chocolate Cream. Attach stump to log and frost with Chocolate Cream. Frost ends of log and branches. Chill until Chocolate Cream is firm.

Decorate as desired, with ''Noel'' or other seasonal words, using decorating frosting and pastry tube.

Store in cool place until used so butter in frosting does not soften. Cake can be frozen. Makes 12 servings. Syrup 1/4 cup sugar 1/4 cup water 1 teaspoon vanilla or almond flavoring

Boil sugar and water together until syrupy, about 3 minutes. Cool and add flavoring. Chocolate Cream Filling and Frosting 2/3 cup sugar 1/3 cup water 2 egg yolks 1 cup soft butter 1 1/2 squares (ounces) chocolate, melted 1 1/2 tablespoons vanilla or almond flavoring

Boil sugar and water together to 240 degrees F., or until soft ball forms in cold water. While syrup is cooking, beat egg yolks until fluffy. Add syrup gradually, while beating, and continue beating until mixture is cool. Add butter , bit by bit, until all has been beaten in. Add and beat in chocolate and flavoring. Tourtiere 3/4 pound ground pork 3/4 pound ground veal 1/2 teaspoon salt 1/4 teaspoon ground cloves

1/2 cup water

1/2 cup bread crumbs

Combine all ingredients except bread crumbs in saucepan. Bring to boil and cook, uncovered, 20 minutes over medium heat. Remove from heat and add bread crumbs. Let stand 10 minutes to allow fat to be absorbed.

Cool and pour into 9-inch pastry lined pan. Cover with top crust. Make vents.

Bake at 400 degrees F. until golden brown. Serve hot. Can be frozen and reheated.