Lemon Upside-Down Dessert

9 very thin lemon slices
1/2 cup granulated sugar
1 tablespoon cornstarch
1/8 teaspoon salt
1/4 cup plus 2 tablespoons hot water
1 tablespoon plus 2 teaspoons lemon juice
2 tablespoons margarine
1/2 teaspoon grated lemon peel
1 1/2 cups Bisquick
1/2 cup granulated sugar
1 egg
1/2 cup milk
2 tablespoons shortening
1 teaspoon vanilla extract

Grease an 8-inch square pan or a 9-inch round pan. Arrange lemon slices in pan.

Mix 1/2 cup sugar, cornstarch and salt in 1 quart saucepan. Stir in hot water and lemon juice. Heat to boiling over medium heat, stirring constantly. Boil and stir 1 minute. Remove from heat, stir in margarine until melted. Mix in lemon peel. Spoon over lemon slices.

Heat oven to 350 degrees F.

Beat remaining ingredients in large bowl on low, scraping bowl constantly, 30 seconds. Beat on medium, scraping bowl occasionally, 4 minutes. Pour into pan. Bake until wooden pick inserted in center comes out clean, 35 to 40 minutes. Immediately invert pan on heatproof plate. Leave in pan for a few minutes.

Clear Lemon Filling
3/4 cup granulated sugar
3 tablespoons cornstarch
1/4 teaspoon salt
3/4 cup water
1 teaspoon grated lemon peel
1 tablespoon margarine or butter
1/3 cup lemon juice
4 drops yellow food color (optional)

Mix sugar, cornstarch and salt in saucepan. Stir in water gradually. Cook, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute. Remove from heat. Add lemon peel and margarine. Stir in lemon juice and food color; cool. If filling is too soft, refrigerate until set.