THERE ARE few pleasures left to city bus riders. The greatest is stepping off. The second greatest is grazing on ripe mulberry trees hanging over city sidewalks in June.

It's the season when bus riders, raincoat and briefcase in one hand, stand like stunned giraffes under swaying branches, picking off little purple berries as fast as hand can reach mouth. It's wonder more mulberry fanciers don't bring plastic bags so they can share them at home. Or perhaps they prefer to leave some for future bus riders.

Fortunately, selfish sparrows and starlings see fit to leave mulberry trees alone. They probably prefer the orange supermarket birdseed found in bowls on innumerable apartment balconies.

Mulberries are not God's greatest gift. Noah probably ignored them. They do not have the spectacular, tart flavor of raspberries. Nor do they have the rich mellowness of blueberries.But they are pleasant, sweet, very purple and, for all practical purposes, seedless. And mulberries grow in great abundance on trees that are easily climbed or reached by ladder.

Why ignore a gift? It's all around us, growing along property lines, creeks, rivers and in fields. Let's keep the frozen raspberries in the freezer for another two weeks and take advantage of something that didn't require standing in line. RING AROUND THE MULBERRY RING (10 servings)

This is an elegant summer dessert that makes superstars out of otherwise ordinary berries. Cream puff dough: 1 cup water 4 tablespoons lightly salted butter 1/2 teaspoon salt 1 tablespoon granulated sugar 1 cup flour 4 eggs Pastry cream: 1 cup milk 1/4 cup granulated sugar 1 tablespoon cornstarch 3 egg yolks 1/2 teaspoon vanilla extract Whipped creams: Plain: 1 cup whipping cream 2 tablespoons confectioners' sugar 1/2 teaspoon vanilla extract 1/2 teaspoon rum Mulberry flavored: 1 cup whipping cream 2 tablespoons confectioners' sugar 1/2 teaspoon vanilla extract 1/2 teaspoon rum 1/2 cup mulberries Ring assembly: 1 1/2 to 2 cups ripe mulberries Confectioners' sugar for dusting

Preheat the oven to 400 degrees. To make the cream puff dough, bring the water, butter, salt and granulated sugar to a boil, add the flour all at once, remove the pan from the fire and stir vigorously until the dough gathers together in a ball and looks almost smooth. But the dough in the bowl of your electric mixer and beat vigorously while adding the 4 eggs, 1 egg at a time, until the dough is smooth and shiny. Pipe the dough out of the pastry bag with a #4 plain tip. Make a circle 9 inches in diameter on a cookie sheet. Then pipe another circle just outside this one and finally one on top of the line between the two circles. Bake until the sides are firm, about 35 minutes.

To make the pastry cream, bring the milk to a boil in a saucepan.Mix the granulated sugar and cornstarch together, then whisk into the yolks until smooth. Pour 1/4 of the hot milk onto the yolk mixture and whisk vigorously. Add another half of the milk, whisk and pour back into the saucepan. Reduce the flame to simmer and whisk the pastry cream, especially the corners where it tends to form lumps. Whisk continually until the pastry cream comes to a boil. Keep heating and stirring 5 minutes after it has begun to bubble. Pour the cooked cream back into the mixing bowl, add vanilla and whisk for 1 minute. Then cover with plastic wrap (which prevents formation of a tough skin), leaving a 1-inch hole for the steam to escape. Set the bowl in cold water to cool if faster.

To make the whipped creams, use two separate bowls. For each, whip cream until stiff, add the confectioners' sugar and flavorings and whip another 20 seconds.

To assemble, cut the cream puff ring in half. With a pastry bag filled with a #4 star tip, pipe 2 rims of pastry cream around the bottom ring half. Fill the space between the 2 rims with the mulberries. Using the same pastry bag and tip (no need to clean), pipe large decorative dollops of plains whipped cream every 2 inches on top of the berries and pastry cream. Fill the gaps with the same size dollops of berry-flavored whipped cream and set the top half of the ring on top of the 2-flavored whipped cream layer. Dust with powered sugar and serve. Mulberry turnover cookies (Makes 18) 2 cups flour 3 tablespoons sugar 1 1/2 sticks lightly salted butter, cut into small pieces 1/2 teaspoon salt 1 teaspoon grated lemon rind 3 hard-cooked egg yolks, cold, rubbed through a sieve 2 raw egg whites 1 egg, beaten, for egg wash

Preheat oven to 375 degrees. Put all ingredients except the egg whites and whole egg in a mixing bowl and work them together quickly with the fingers, mashing the butter into the flour and then rubbing it between your palms until the mixture resembles coarse cornmeal. Add the egg whites and work the dough into a ball. Enclose in foil or plastic wrap and refrigerate until ready to use. Roll the dough to a thickness of 1/8 inch on a liberally floured board. It will crack -- just push the dough back together. Run a spatula underneath to free it from the board and remove excess flour. Cut into 3-by-3-inch squares, place 4 or 5 mulberries in the middle of each, moisten the edges and fold into triangles. Brush each turnover cookie with the beaten egg and bake about 25 minutes or until golden brown. VIENNESE MULBERRY SHORTBREAD (10 servings) 1 batch turnover cookie dough) recipe above) 1/2 cup mulberry or other berry jam 3 egg whites 1/2 cup granulated sugar 1 cup fresh mulberries Confectioners' sugar for dusting

Preheat oven to 375 degrees. Make 1 batch of turnover cookie dough and roll out to fit a cookie sheet. Cut in half crosswise, patch up any torn edges and bake until golden brown and firm, about 15 minutes. Remove from oven and turn up oven to 550 degrees. Smear 1 half of the baked cookie dough with jam and invert the other half on top. Its flat side should face up. Whip 3 egg whites until they form soft peaks. Add the sugar gradually while whipping. When stiff, fold in the cup of mulberries. Smear this meringue over the shortbread with a spatula, lifting it periodically to form soft peaks. Place in 550-degree oven for 3 to 5 minutes or until the meringue has browned to the desired color. Remove, let cool and sprinkle with confectioners' sugar. Serve. MULBERRY SAUCE (Makes about 2 cups)

Use on pancakes, waffles, french toast and ice cream. 1/2 cup sugar 2 teaspoons cornstarch Dash of salt 1/2 cup water 2 cups mulberries* 1 teaspoon lemon juice 1/2 teaspoon grated lemon rind (optional)

Mix sugar and cornstarch together and add to the salt and water. Bring slowly to a boil, stirring. Add the mulberries, lemon juice and rind. Boil 2 minutes to cool.

*Note: Any berry sauce can be made this way, simply substitute your favorite berry. MULBERRY JAM OR JELLY (Makes 2 pints) 2 cups red berries (unripe) 2 cups purple berries 1/4 cup water 1 tablespoon lemon juice 2 cups sugar 1 envelope liquid fruit pectin

For jelly, simmer the fruit with the water for 10 minutes. Strain through a jelly bag, taking care not to squeeze if clear jelly is desired. Otherwise, squeeze away. Add the lemon juice and sugar to the liquid and return to boil, stir in the pectin, boil 1 minute. Pour into clean jars and let cool 5 minutes before pouring on paraffin.

For jam, bring berries, water, lemon juice and sugar to a boil. Add pectin, boil 1 minute and cool. Do not bottle the jam until it has cooled almost to room temperature; otherwise the fruit will float to the top of the jars.