JOAN SPECTER'S children often complained about what she served them as they were growing up. Never the same thing twice.

"Cooking was one give experiment for what I would teach in my classes," Specter explained as she beat the filling for her caramel pineapple cake, the cake she makes every year for her husband's birthday. "We had some very exotic food for 3-year-olds."

But teaching cooking was just an 11-year phase in Specter's career. She began with a friend in Philadelphia in 1964, in the days when a knowledge of cooking was all that was necessary to become an immediate success at teaching. "We were good cooks, and a lot of our friends wanted to learn to cook." Five years later, after studying with Jim Beard in New York, at the Cordon Bleu in London and the Culinary Institute of America, Specter owned the cooking school by herself.

By 1975 she was bored. "I had tought every chicken dish there was. I was sick of it," she said, as she tried to figure out why the caramel filling wouldn't firm up.

"I must admit this is culture shock for me," she added, referring to a morning or marathon cooking. Specter hasn't spent much time in the kitchen in the last year, since she was elected to Philadelphia City Council and since her husband Arlen won a seat representing Pennsylvania in thef U.S. Senate. "I don't think I've entertained for a year except New Year's Eve for my husband. I do that every year."

The Specters didn't plan 1980 the way it happened. Joan Specter says that if she had known her husband was going to run for office again -- he had been district attorney in Philadelphia -- she's not sure she would have run for City Council. Among other problems, it means living apart for some of each week and maintaining two households. The Specters have just purchased a condominium in Georgetown.

But the City Coucil job isn't the only thing that keeps Specter in Philadelphia. When she tired of teaching, she looked around for another job and -- after some newspaper writing and a stint as a consumer reporter on a local radio station -- received one of those fateful phone calls that you read about in novels. "One day a young retired man called me. He wanted to open a bakery."

Four years ago Specter began baking pies commercially, but not before she had spent four months, working five hours a day every day, to perfect an apple pie. "I knew America's best seller was apple so I tried to develop an apple pie that was different. I knew I wanted it to have fresh apples. I knew I didn't want a top crust because I just don't think people eat crust. The trick was to get the mixture to hold together. That was really, really hard. It ran a lot in the beginning," Specter recalled with a laugh.

"We all got sick of eating apple pie and said we'd never eat another apple as long as we lived."

In developing her recipe, Specter had one advantage most commercial bakers don't: Cost was not a factor. "I never considered cost. It was to be the best apple pie I could ever make. The other thing was that I wanted it to be without preservatives, and I was able to make it that way."

Then Specter decided that if the company were to be a success it would need more than one pie. So she began work oin the next-best seller after apple, which was chocolate. "It was a snap to make that one. I took a combination of things I had done before and made it with good chocolate and lots of heavy cream."

In the beginning, Specter and one other woman did all the baking. Specter continued to bake from time to time for the first two years. But now she has eight bakers and she sticks to supervision of quality control. She doesn't feel that the quality of the pies has deteriorated because she is no longer baking. "I don't think the quality has to fall off, because we do an awful lot of the work by hand. It doesn't really drop off until you get into a lot of big machinery."

The pies have been an enormous success. Washington area restaurants, the Palm and the Rib in Rockville among them, serve Joan Specter's Desserts. But Specter says she doesn't know where else they are served because her distributor won't tell her. Despite the truth-in-menu regulations prohibiting a restaurant from describing something as prepared on the premises if it wasn't, some restaurants apparently still make that claim with her desserts.

Specter has pies in distribution all over the Northeast, Mid-Atlantic states and parts of the Southeast. She has plans to open outlets in Houston and Chicago this year. Her oldest son, Shanin, is working for the company between his stint with his father's senatorial race and law school.

The company makes four different varieties: double chocolate mousse, peach almond cream, vanilla chip cream and candied apple walnut. In Philadelphia they are available at retail for $16 to $18. They are supposed to serve 16 people, 4 ounces each. At the Palm each pie is cut into 10 slices.

There aren't too many things Specter does at which she has not been an unqualified success. There aren't too many things she has wanted to do that she hasn't except . . .

"One of the things I always wanted that I didn't get was to be food editor of the Philadelphia Inquirer. I went to see Elaine Tait (then and now food editor) and realized she was a contemporary and . . .

"I also wanted to be food editor at the Ladies' Home Journal, but I wouldn't live in New York and they insisted. I would have commuted, but it probably would have been awful for my marriage.

"I've had a great life," Specter said. "I've always been able to do everything I've ever wanted. I've always known what I wanted to do . . . I've always been active with my husband in politics and decided, after 15 years of watching people walk to the front of a room and make their speeches, I had something to contribute, too."

Specter is one of three Republican members of the 17-member City Council, and, as an avid supporter of women's issues, pushed through a city ordinance prohibiting discrimination in private clubs.

Despite commuting, furnishing a new home, directing a commercial bakery that makes 2,000 pies a week and playing an active role on the City Council, Specter still made time to prepare New Year's Eve dinner for her husband, as she has for the past eight years.

First course: paupiette of sole with salmon in a tomato-basil sauce. Second course: thin egg noodles with pork, sweet bean paste and thinly sliced scallions. Third course: quail in mustard cream sauce, potato baskets with glazed water chestnuts cut to look like quail eggs and snow peas. Fourth course: brie and puff pastry with currant jelly and grapes. Fifth course: glazed poached oranges with kiwis. To drink: champagne.

If you are only going to cook once a year it might as well be spectacular. TARTE A LA TATIN (12 or more servings) Crust: 2 cups flour 1 teaspoon salt 2 tablespoons sugar 1/4 pound plus 2 tablespoons butter 1 egg yolk Juice of 1 lemon 4 to 6 tablespoons water

Mix flour, salt and sugar. Cut in butter until mixture resembles coarse cornmeal. Add liquids. Form into ball. Refrigerate 30 minutes. Roll out to fit frying pan that is 12 inches in diameter at the top. Sauce: 1/4 pound butter 1/2 cup sugar 7 to 9 small york, winesap or granny smith apples, peeled, cored and halved

Melt butter and sugar in skillet that is 12 inches in diameter at the top. Place apple halves in butter, round side up. Cook over low heat 35 to 40 minutes, turning halfway through cooking and again a few minutes before they are finished. Cook until light golden in color and caramelized. Fit crust over apples, folding edges of crust under itself. Bake at 400 degrees for 20 to 30 minutes, until crust is golden brown. Turn out immediately and serve warm. CARAMEL PINEAPPLE CAKE (8 servings) 1 cup solid vegetable shortening 1 cup sugar 1 whole egg 3 eggs, separated 1 1/2 cups cake flour 1/2 cup milk 2 teaspoons vanilla 8-ounce can crushed pineapple, well-drained 2 teaspoons baking powder

Butter 2 8-inch baking pans and line with waxed paper. Beat shortening and sugar until light. Add whole egg and 3 yolks, 1 at a time, beating to blend between each addition. Fold in flour and milk, alternately. Add vanilla and pineapple. Beat whites until stiff but not dry. Sprinkle baking powder over flour mixture and fold in whites. Bake at 350 degrees for 30 minutes.Allow cakes to sit a moment before turning out of pans onto greased cake racks. When cool, split in half horizontally. Caramel Nut Filling: 1 cup white sugar 1 cup dark brown sugar 1/2 cup milk 1/4 pound butter 1 1/2 teaspoons vanilla 1/2 cup chopped walnuts

Combine first 4 ingredients in saucepan. Bring to boil and let boil 2 minutes without stirring. Remove from heat; add vanilla. Beat until thick and cool. Fold in nuts. Spread between layers of cake but not on top. Icing: 1 cup pure maple syrup 1/2 cup egg whites Candied violets for decoration

Bring syrup to boild and boil for 5 minutes. Beat whites until they form soft peaks. Slowly pour syrup in, beating until stiff. Spread on top and sides of cake. Garnish with violets. CANDIED ORANGE TART (8 servings) Pastry: 1 1/2 cups flour 1 teaspoon salt 1/4 cup sugar 1/4 cup butter plus 2 tablespoons 1 egg yolk 1 tablespoon lemon juice 3 to 4 tablespoons water

Mix flour, salt and sugar. Cut in butter until mixture resembles coarse cornmeal. Add liquids. Refrigerate 30 minutes. Roll out to fit 9-inch flan ring. Butter pan; fit dough into it, pressing against bottom and sides and cutting off excess. Line with waxed paper and weight with dried beans or other pie-shell weights. Bake at 425 degrees 5 minutes. Remove paper and weights and bake 6 to 7 minutes longer, until golden. Cool and fill. Filling: 8 ounces cream cheese, softened 1/4 cup sugar 3 tablespoons Cointreau 1/2 cup heavy cream 3/4 cup orange marmalade 2 thin-skinned oranges, thinly sliced Seeded grapes Candied walnuts (optional)

Beat cheese and sugar with Cointreau in electric mixer until smooth. Gradually add cream and continue beating until fluffy. Spread on cooled pastry. Chill. Heat marmalade and strain. There should be 1/2 cup. Arrange orange slices over filling, using grapes to fill in blank spaces. Brush all over with marmalade to glaze.Top with candied walnuts, if desired.

To make candied walnuts: Melt 1/2 cup sugar in heavy saucepan until it becomes liquid and light amber in color. Arrange small clusters of 3 small walnut halves on greased cookie sheet. Make enough clusters to top each orange slice. Pour melted sugar over clusters. Work quickly. The effect is a piece of walnut brittle atop each orange.