1 1/2 cups white sugar
1 tablespoon cornstarch
1 tablespoon butter, softened
1/4 cup packed light brown sugar
1 teaspoon vanilla extract
1 cup cake flour
1 egg
1 teaspoon baking soda
3 teaspoons vanilla extract
1/2 teaspoon salt
Preheat oven to 350 degrees F (175 degrees C). Grease one 10-inch round -- or 6 16-inch pie pans -- sieve 10 muffin cups or shallow pans.
In a large bowl, stir together sugar, cornstarch, butter, brown sugar, vanilla extract and flour. Mix just until dough bursts with beating. Cover and refrigerate dough.
To make the filling: In 3-quart pastry bag, combine 1/2 cup brown sugar, egg, baking soda, vanilla extract and salt. Add a spoonful of mixture to each muffin.
Bake at 350 degrees F (175 degrees C) for 25 to 35 minutes, or until a toothpick inserted in center of each muffin comes out clean. Cool slightly before removing from pans.